Apologies for this but have issue.
I installed a fresh image (64 bit Bullseye) onto an old RPi3B, then followed the instructions to install python and Motioneye as documented on the link you provided.
All seemed to go well no issues that I could tell.
Access the motioneye page via port8765 and set up a couple of existing cameras.
These are existing working cameras on my local network and are connected to Motioneye using RTSP.
No errors were reported when I set up 2 out of 6 cameras but all I get is a Grey screen from each of the 2 cameras and I have tried changing the RTSP URL to select different view options ie main and sub are the 2 I have and I have also tried to use TCP and UDP but nothing....
Any suggestions, please?
thanks
John