Reolink video PoE Videodoor bell does not record 24/7

[user_886109714321649_886109714321649]

Hi all,

I have 4x 833A and 1x Video Doorbell PoE connected to a RLN8-410. All my cameras record 24/7 without any interruptions but the doorbell always has "black bars" where no video footage is recorded.
1 of 10 days it records 24/7 but the remaining 9 days show a lot of gaps.

The doorbell is reachable by the Reolink app (~ 80% of the time) but sometimes also cannot connect. I guess in that time in also does not record. But the strange thing is, you can still go out and ring the bell and everything works fine, although the app shows no connection.
I assume it might be a cable problem but I am not sure ...

Any help is greatly appreciated !