Hi,
For streaming, please set the properties: insert-sps-pps and idrinterval=15. There is reference command in the post:
Gstreamer TCPserversink 2-3 seconds latency - #5 by DaneLLL
And not sure how you launch the RTSP server. You may try test-launch. Please refer to
Jetson Nano FAQ
Q: Is there any example of running RTSP streaming?