[GH-ISSUE #778] [Bug Report] Tried to print a sliced plate, the queue says it has been moved to the printing #518

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opened 2026-05-07 00:11:12 +02:00 by BreizhHardware · 3 comments

BreizhHardware commented

2026-05-07 00:11:12 +02:00

Owner

Originally created by @maziggy on GitHub (Mar 21, 2026).
Original GitHub issue: https://github.com/maziggy/bambuddy/issues/778

Originally assigned to: @maziggy on GitHub.

Tried to print a sliced plate, the queue says it has been moved to the printing state. But the printer never starts printing. Earlier print fine, the second one today doesnt wat to start. I already resliced and re-uploaded the sliced 3mf like usually, but no joy somehow.

Reporter Contact

Email: rubenkremer@gmail.com

System Information

{
  "generated_at": "2026-03-21T19:17:30.642061",
  "app": {
    "version": "0.2.2",
    "debug_mode": false
  },
  "system": {
    "platform": "Linux",
    "platform_release": "6.12.54-Unraid",
    "platform_version": "#1 SMP PREEMPT_DYNAMIC Tue Oct 21 15:58:46 PDT 2025",
    "architecture": "x86_64",
    "python_version": "3.13.12"
  },
  "environment": {
    "docker": true,
    "data_dir": "/app/data",
    "log_dir": "/app/logs",
    "timezone": "Europe/Amsterdam"
  },
  "database": {
    "archives_total": 14,
    "archives_completed": 12,
    "printers_total": 1,
    "filaments_total": 0,
    "projects_total": 5,
    "smart_plugs_total": 1
  },
  "printers": [
    {
      "index": 1,
      "model": "A1",
      "nozzle_count": 1,
      "is_active": true,
      "mqtt_connected": true,
      "state": "IDLE",
      "firmware_version": "01.07.02.00",
      "wifi_signal": -41,
      "reachable": true,
      "ams_unit_count": 0,
      "ams_tray_count": 0,
      "has_vt_tray": true,
      "external_camera_configured": false,
      "plate_detection_enabled": false,
      "hms_error_count": 0,
      "developer_mode": null,
      "nozzle_rack_count": 0
    }
  ],
  "settings": {
    "auth_enabled": "false",
    "setup_completed": "true",
    "auto_archive": "true",
    "save_thumbnails": "true",
    "capture_finish_photo": "true",
    "default_filament_cost": "20.0",
    "currency": "EUR",
    "energy_cost_per_kwh": "0.15",
    "energy_tracking_mode": "total",
    "check_updates": "true",
    "check_printer_firmware": "true",
    "include_beta_updates": "false",
    "notification_language": "en",
    "bed_cooled_threshold": "35.0",
    "ams_humidity_good": "40",
    "ams_humidity_fair": "60",
    "ams_temp_good": "28.0",
    "ams_temp_fair": "35.0",
    "ams_history_retention_days": "30",
    "per_printer_mapping_expanded": "false",
    "date_format": "eu",
    "time_format": "24h",
    "default_printer_id": "1",
    "ftp_retry_enabled": "true",
    "ftp_retry_count": "3",
    "ftp_retry_delay": "2",
    "ftp_timeout": "30",
    "mqtt_enabled": "false",
    "mqtt_broker": "",
    "mqtt_port": "1883",
    "mqtt_topic_prefix": "bambuddy",
    "mqtt_use_tls": "false",
    "ha_enabled": "true",
    "library_archive_mode": "always",
    "library_disk_warning_gb": "5.0",
    "camera_view_mode": "embedded",
    "preferred_slicer": "bambu_studio",
    "prometheus_enabled": "false"
  },
  "docker": {
    "container_memory_limit_bytes": null,
    "container_memory_limit_formatted": null,
    "network_mode_hint": "host"
  },
  "virtual_printers": [
    {
      "index": 1,
      "enabled": false,
      "mode": "print_queue",
      "model": "N2S",
      "model_name": "A1",
      "has_target_printer": true,
      "has_bind_ip": true,
      "running": false,
      "pending_files": 0
    }
  ],
  "integrations": {
    "notification_providers": [
      {
        "type": "ntfy",
        "enabled": true,
        "has_last_error": false
      }
    ],
    "spoolman": {
      "enabled": false,
      "reachable": false
    },
    "mqtt_relay": {
      "enabled": false,
      "connected": false,
      "broker": "",
      "port": 0,
      "topic_prefix": "bambuddy"
    },
    "homeassistant": {
      "enabled": true
    }
  },
  "database_health": {
    "journal_mode": "wal",
    "quick_check": "ok",
    "db_size_bytes": 425984,
    "wal_size_bytes": 4120032
  },
  "dependencies": {
    "fastapi": "0.135.1",
    "uvicorn": "0.42.0",
    "pydantic": "2.12.5",
    "sqlalchemy": "2.0.48",
    "paho-mqtt": "2.1.0",
    "psutil": "7.2.2",
    "httpx": "0.28.1",
    "aiofiles": "25.1.0",
    "cryptography": "46.0.5",
    "opencv-python-headless": "4.13.0.92",
    "numpy": "2.4.3"
  },
  "log_file": {
    "size_bytes": 1000960,
    "size_formatted": "977.5 KB"
  },
  "network": {
    "interface_count": 2,
    "interfaces": [
      {
        "name": "br0",
        "subnet": "x.x.1.0/24"
      },
      {
        "name": "wg0",
        "subnet": "x.x.0.1/32"
      }
    ]
  },
  "websockets": {
    "active_connections": 1
  }
}

Logs (sanitized): bambuddy.log

Submitted via BamBuddy Bug Report

Originally created by @maziggy on GitHub (Mar 21, 2026). Original GitHub issue: https://github.com/maziggy/bambuddy/issues/778 Originally assigned to: @maziggy on GitHub. Tried to print a sliced plate, the queue says it has been moved to the printing state. But the printer never starts printing. Earlier print fine, the second one today doesnt wat to start. I already resliced and re-uploaded the sliced 3mf like usually, but no joy somehow. <details> <summary>Reporter Contact</summary> Email: rubenkremer@gmail.com </details> <details> <summary>System Information</summary> ```json { "generated_at": "2026-03-21T19:17:30.642061", "app": { "version": "0.2.2", "debug_mode": false }, "system": { "platform": "Linux", "platform_release": "6.12.54-Unraid", "platform_version": "#1 SMP PREEMPT_DYNAMIC Tue Oct 21 15:58:46 PDT 2025", "architecture": "x86_64", "python_version": "3.13.12" }, "environment": { "docker": true, "data_dir": "/app/data", "log_dir": "/app/logs", "timezone": "Europe/Amsterdam" }, "database": { "archives_total": 14, "archives_completed": 12, "printers_total": 1, "filaments_total": 0, "projects_total": 5, "smart_plugs_total": 1 }, "printers": [ { "index": 1, "model": "A1", "nozzle_count": 1, "is_active": true, "mqtt_connected": true, "state": "IDLE", "firmware_version": "01.07.02.00", "wifi_signal": -41, "reachable": true, "ams_unit_count": 0, "ams_tray_count": 0, "has_vt_tray": true, "external_camera_configured": false, "plate_detection_enabled": false, "hms_error_count": 0, "developer_mode": null, "nozzle_rack_count": 0 } ], "settings": { "auth_enabled": "false", "setup_completed": "true", "auto_archive": "true", "save_thumbnails": "true", "capture_finish_photo": "true", "default_filament_cost": "20.0", "currency": "EUR", "energy_cost_per_kwh": "0.15", "energy_tracking_mode": "total", "check_updates": "true", "check_printer_firmware": "true", "include_beta_updates": "false", "notification_language": "en", "bed_cooled_threshold": "35.0", "ams_humidity_good": "40", "ams_humidity_fair": "60", "ams_temp_good": "28.0", "ams_temp_fair": "35.0", "ams_history_retention_days": "30", "per_printer_mapping_expanded": "false", "date_format": "eu", "time_format": "24h", "default_printer_id": "1", "ftp_retry_enabled": "true", "ftp_retry_count": "3", "ftp_retry_delay": "2", "ftp_timeout": "30", "mqtt_enabled": "false", "mqtt_broker": "", "mqtt_port": "1883", "mqtt_topic_prefix": "bambuddy", "mqtt_use_tls": "false", "ha_enabled": "true", "library_archive_mode": "always", "library_disk_warning_gb": "5.0", "camera_view_mode": "embedded", "preferred_slicer": "bambu_studio", "prometheus_enabled": "false" }, "docker": { "container_memory_limit_bytes": null, "container_memory_limit_formatted": null, "network_mode_hint": "host" }, "virtual_printers": [ { "index": 1, "enabled": false, "mode": "print_queue", "model": "N2S", "model_name": "A1", "has_target_printer": true, "has_bind_ip": true, "running": false, "pending_files": 0 } ], "integrations": { "notification_providers": [ { "type": "ntfy", "enabled": true, "has_last_error": false } ], "spoolman": { "enabled": false, "reachable": false }, "mqtt_relay": { "enabled": false, "connected": false, "broker": "", "port": 0, "topic_prefix": "bambuddy" }, "homeassistant": { "enabled": true } }, "database_health": { "journal_mode": "wal", "quick_check": "ok", "db_size_bytes": 425984, "wal_size_bytes": 4120032 }, "dependencies": { "fastapi": "0.135.1", "uvicorn": "0.42.0", "pydantic": "2.12.5", "sqlalchemy": "2.0.48", "paho-mqtt": "2.1.0", "psutil": "7.2.2", "httpx": "0.28.1", "aiofiles": "25.1.0", "cryptography": "46.0.5", "opencv-python-headless": "4.13.0.92", "numpy": "2.4.3" }, "log_file": { "size_bytes": 1000960, "size_formatted": "977.5 KB" }, "network": { "interface_count": 2, "interfaces": [ { "name": "br0", "subnet": "x.x.1.0/24" }, { "name": "wg0", "subnet": "x.x.0.1/32" } ] }, "websockets": { "active_connections": 1 } } ``` </details> **Logs (sanitized):** [bambuddy.log](https://raw.githubusercontent.com/maziggy/bambuddy/bug-report-assets/logs/222dd474f8a441469a97fdb9e43a5e3a.log) --- *Submitted via BamBuddy Bug Report*

BreizhHardware

2026-05-07 00:11:12 +02:00

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BreizhHardware commented

2026-05-07 00:11:12 +02:00

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@RubenKremer commented on GitHub (Mar 21, 2026):

Changed it from a specific A1 to Any A1 and that seems to have worked. Now the print has commenced.

@RubenKremer commented on GitHub (Mar 21, 2026): Changed it from a specific A1 to Any A1 and that seems to have worked. Now the print has commenced.

BreizhHardware commented

2026-05-07 00:11:12 +02:00

Author

Owner

@maziggy commented on GitHub (Mar 22, 2026):

Root cause: When a queue item targets a specific printer and the scheduler detects it's disconnected, it enters a reconnect loop. Each attempt creates a fresh MQTT client that tries to subscribe to the printer's request topic. Your A1's MQTT broker rejects that subscription by disconnecting, which caused a ~170 second cycle of connect → subscribe → disconnect → repeat. By the time the connection stabilized, it was fragile enough that the print command was silently lost.

Switching to "Any A1" bypassed this entirely because that code path only uses already-connected printers — no reconnect loop, no request topic re-subscription.

Fix: We now cache request topic support per printer serial number, so new client instances immediately skip the subscription instead of rediscovering the rejection each time. This eliminates the thrash loop entirely.

Available/Fixed in branch dev and available with the next release or daily build. Please let me know if it works for you now.

If you find Bambuddy useful, please consider giving it a ⭐ on GitHub — it helps others discover the project!

@maziggy commented on GitHub (Mar 22, 2026): **Root cause**: When a queue item targets a specific printer and the scheduler detects it's disconnected, it enters a reconnect loop. Each attempt creates a fresh MQTT client that tries to subscribe to the printer's request topic. Your A1's MQTT broker rejects that subscription by disconnecting, which caused a ~170 second cycle of connect → subscribe → disconnect → repeat. By the time the connection stabilized, it was fragile enough that the print command was silently lost. Switching to "Any A1" bypassed this entirely because that code path only uses already-connected printers — no reconnect loop, no request topic re-subscription. Fix: We now cache request topic support per printer serial number, so new client instances immediately skip the subscription instead of rediscovering the rejection each time. This eliminates the thrash loop entirely. --- Available/Fixed in branch dev and available with the next release or daily build. Please let me know if it works for you now. ----- If you find Bambuddy useful, please consider giving it a ⭐ on [GitHub](https://github.com/maziggy/bambuddy) — it helps others discover the project!

BreizhHardware commented

2026-05-07 00:11:13 +02:00

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@RubenKremer commented on GitHub (Mar 22, 2026):

Glad to have found a real potential bug instead of human error 😉 ... I'll try the daily version and report back if it occurs again!

@RubenKremer commented on GitHub (Mar 22, 2026): Glad to have found a real potential bug instead of human error 😉 ... I'll try the daily version and report back if it occurs again!