I don’t have NVR so I connect directly to the cameras. I have 10 POE Reolink cameras and the notifications all do work if they are present in the Reolink app. I actually verified this against notifications in the app side by side as the previous Reolink_dev plugins missed about 60% of the notification.
What helped me a lot in clearing Auth errors in the log is moving the 2 sliders in the camera plugin config all the way to the right (something like timeout and subscription). RTSP stream works smoother for me so try that. I don’t think anything can be done about user and pass in the url as it’s how Reolink api works.
I always have had just okaish performance with any camera stream in HA, I think the issue is the size of the stream so it takes a while for it to actually connect and work. I had really good success with WebRTC Lovelace card by AlexxIT. But even with that having 10 cameras request WebRTC stream doesn’t give instant results. Again this is not related to the plugin as the plugin just provides the direct stream.
In Lovelace now I switched to use GitHub - dermotduffy/frigate-hass-card: A Lovelace card for Frigate in Home Assistant Card. You dont need Frigate for it to work and it works with any camera entity, it also automtically decides the best way to stream it (It can even fallback to AlexxIT WebRTC from above).
I have those cards setup to automatically switch to camera with motion when motion is detected and start playback. So all my cameras load on screen at once and are shown as an image that’s updated every few seconds. If any of the cameras have motion those cameras starts live playback automatically and are highlighted (you just define which entities are triggered in the card config).
You can also configure it through UI so you don’t have to worry about all the options that are in the doc.