Hi are you using the FFMpeg backend or GStreamer? If FFMpeg can you try ffplay and see if you have the same issue?
I’m asking because I have been observing weird stalls with RTSP but they are incosistent sometimes after a day sometimes after a week. I thought it was something I was doing wrong (and it could be as I’m always changing the combination of the OpenCV and FFMpeg I’m running) but it “could” be a bug in the RTSP streaming code. If you don’t have the same issue with ffplay then I will start looking into it.