Ok this is now getting silly.
I've got two cameras running RTSP Feeds, a hikvision and a eufy floodlight. Both have got their own integrations, sure, but both don't stream properly so I need to use the RTSP stream via "generic camera" integration.
Neither works.
Regardless of the connection I choose (and i've tried every single combination of TCP/UDP etc. Basic and digest auth. None makes any difference.
Communication isn't an issue.
VLC using my mobile phone can connect to the streams without issue.
Console into my HA container and running ffmpeg -rtsp_transport tcp -i rtsp://username:password@CAMERA_IP/live0 -t 10 -f null - connects and streams fine.
as does webrtc as a card on one of my lovelace pages.
there are some errors in the logs but none are really helping. as I say, i've tried many variations (the rtsp link above with username/pass in the url. also using the username and password specific boxes in the setup.
logs
2025-09-08 16:04:10.810 ERROR (stream_worker) [homeassistant.components.stream.stream.camera.192_168_0_44] Error from stream worker: Unauthorized error opening stream (HTTP_UNAUTHORIZED, Server returned 401 Unauthorized (authorization failed), rtsp://****:****@192.168.0.44/live0)
and the other camera
2025-09-08 15:59:21.553 ERROR (stream_worker) [homeassistant.components.stream.stream.generic.test_stream] Error from stream worker: Error opening stream (ERRORTYPE_5, I/O error, rtsp://****:****@192.168.0.51:554/ISAPI/Streaming/Channels/102)
any pointers? I can't see how it could be a bug when i'm using 2 different cameras and noone else is complaining of issues. but then as i say, I'm using 2 different cameras which work ok elsewhere.