Security camera via zerotier / disconnect

I have multiple security cameras rtsp stream connected well via wifi gli router via fibre and other 4G routers with connected cameras, via zerotier to AWS.

If I stream these rtsp streams via port forwarding the streams are perfectly stable and i can run for a day or more, without any problem.

If I connect from AWS to zerotier and then access the camera IP to start the rtsp stream, all works fine BUT only for 1-5 minutes. Then the stream disconnects, ‘empty pipe, no more packets found’. I have to then re-connect the stream. Basically it is very unstable.
What might be causing this packet instability? How do I resolve this?