File→RTSP (OpenCV+GStreamer→mediamtx) unstable on Jetson; direct RTSP works

Hi,
There is a sample for setting up UDP:
Stream processed video with OpenCV on Jetson TX2 - #5 by DaneLLL

For setting up RTSP through OpenCV, would see if other users can share experience.

FYR, in C code, we can set up RTSP through test-launch:
Jetson AGX Orin FAQ