When I run the setup check it shows this:

File-upload service (port 990)
Nothing is listening on port 990 of the bind IP, so the slicer cannot upload files. A port conflict on this interface is the usual cause.

Using netstat -ntlp, it shows nothing using port 990 when the container is stopped.

The start up logs seem to show that the FTP service was started and showed no errors.

bambuddy  | 2026-08-07 10:23:15,200 INFO [backend.app.services.virtual_printer.manager] [-] [VP Test] Starting server-mode services on 10.0.0.12
bambuddy  | 2026-08-07 10:23:15,200 INFO [backend.app.services.virtual_printer.certificate] [-] Deleted printer certificate (CA preserved)
bambuddy  | 2026-08-07 10:23:15,200 INFO [backend.app.services.virtual_printer.certificate] [-] Generating certificates for virtual printer (serial: 03900A391800002)...
bambuddy  | 2026-08-07 10:23:15,254 INFO [backend.app.services.virtual_printer.certificate] [-] Using existing CA certificate (expires in 7147 days)
bambuddy  | 2026-08-07 10:23:15,302 WARNING [backend.app.services.bambu_mqtt] [-] [03919C440802216] MQTT disconnected: rc=Unspecified error, flags=DisconnectFlags(is_disconnect_packet_from_server=False)
bambuddy  | 2026-08-07 10:23:15,302 WARNING [backend.app.services.bambu_mqtt] [-] [03919C440802216] Disconnected shortly after request topic subscription. Disabling request topic for this printer.
bambuddy  | 2026-08-07 10:23:15,384 INFO [backend.app.services.virtual_printer.certificate] [-] Generating printer certificate with CN=03900A391800002, local IP: 10.0.0.12
bambuddy  | 2026-08-07 10:23:15,389 INFO [backend.app.services.virtual_printer.certificate] [-] Generated certificate chain at /app/data/virtual_printer/certs/2
bambuddy  | 2026-08-07 10:23:15,389 INFO [backend.app.services.virtual_printer.certificate] [-]   CA: CN=Virtual Printer CA
bambuddy  | 2026-08-07 10:23:15,389 INFO [backend.app.services.virtual_printer.certificate] [-]   Printer: CN=03900A391800002
bambuddy  | 2026-08-07 10:23:15,389 INFO [backend.app.services.virtual_printer.mqtt_bridge] [-] [Test] MQTT bridge IP encoding armed: target=10.0.20.127 vp=10.0.0.12 (bind_address)
bambuddy  | 2026-08-07 10:23:15,389 INFO [backend.app.services.virtual_printer.mqtt_bridge] [-] [Test] MQTT bridge bound to printer 1 (serial=03919X420802216)
bambuddy  | 2026-08-07 10:23:15,390 INFO [backend.app.services.virtual_printer.ftp_server] [-] [Test] Starting virtual printer implicit FTPS on 10.0.0.12:990
bambuddy  | 2026-08-07 10:23:15,391 INFO [backend.app.services.virtual_printer.ftp_server] [-] FTP SSL context created with standard settings
bambuddy  | 2026-08-07 10:23:15,391 INFO [backend.app.services.virtual_printer.mqtt_server] [-] Starting simple MQTT server on port 8883
bambuddy  | 2026-08-07 10:23:15,412 INFO [backend.app.services.virtual_printer.mqtt_server] [-] MQTT SSL cert info: subject=CN=03900A391800002
bambuddy  | issuer=CN=Virtual Printer CA
bambuddy  | 2026-08-07 10:23:15,412 INFO [backend.app.services.virtual_printer.mqtt_server] [-] MQTT SSL context: TLS 1.2+, cert=/app/data/virtual_printer/certs/2/virtual_printer.crt
bambuddy  | 2026-08-07 10:23:15,412 INFO [backend.app.services.virtual_printer.tcp_proxy] [-] Starting Camera-6000 TCP proxy: 10.0.0.12:6000 → 10.0.20.127:6000
bambuddy  | 2026-08-07 10:23:15,413 INFO [backend.app.services.virtual_printer.bind_server] [-] Starting bind server on ports [3000, 3002] (serial=03900A391800002, model=N2S, tls=True)
bambuddy  | 2026-08-07 10:23:15,413 INFO [backend.app.services.virtual_printer.ssdp_server] [-] Starting virtual printer SSDP server: Test (03900A391800002)
bambuddy  | 2026-08-07 10:23:15,414 INFO [backend.app.services.virtual_printer.ssdp_server] [-] SSDP server listening on port 2021, advertising IP: 10.0.0.12
bambuddy  | 2026-08-07 10:23:15,414 INFO [backend.app.services.virtual_printer.ssdp_server] [-] Virtual printer: Test (03900A391800002) model=N2S
bambuddy  | 2026-08-07 10:23:15,414 INFO [backend.app.services.virtual_printer.ssdp_server] [-] SSDP server also listening on 0.0.0.0:2021
bambuddy  | 2026-08-07 10:23:15,414 INFO [backend.app.services.virtual_printer.ssdp_server] [-] Sent initial SSDP NOTIFY announcement
bambuddy  | 2026-08-07 10:23:15,419 INFO [backend.app.main] [-] [#1752] Printer 1 connected→disconnected edge; scheduling offline notification in 60s
bambuddy  | 2026-08-07 10:23:15,420 INFO [backend.app.services.virtual_printer.ftp_server] [-] Implicit FTPS server started on port 990
bambuddy  | 2026-08-07 10:23:15,420 INFO [backend.app.services.virtual_printer.ftp_server] [-] FTP passive data port range: 50010-50019
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.mqtt_server] [-] Simple MQTT server listening on port 8883
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.tcp_proxy] [-] Camera-6000 TCP proxy listening on port 6000
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.bind_server] [-] Bind server listening on 10.0.0.12:3000 (plain)
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.mqtt_server] [-] Starting periodic status push task
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.bind_server] [-] Bind server listening on 10.0.0.12:3002 (TLS)
bambuddy  | 2026-08-07 10:23:15,421 INFO [backend.app.services.virtual_printer.manager] [-] [VP Test] Server-mode services started on 10.0.0.12
bambuddy  | 2026-08-07 10:23:15,422 INFO [backend.app.services.virtual_printer.manager] [-] Started server-mode VP: Test on 10.0.0.12
bambuddy  | 2026-08-07 10:23:15,422 INFO [root] [-] Virtual printer manager synced from database