When ever more than 2 join audio and video disconnects

Using Jitsi Docker as self hosted server and iframe APIs to call in frontend
When ever 3rd person joins, the video and audio gets disconnected.
when a third person leaves then video and audio is back.

why is this and how many can connect with video and audio in one conference?

Check your firewall. Make sure all required ports are open and accessible. Check port 10000/udp especially - make sure it’s open and properly forwarded if behind a NAT.

I tried But still same issue.
I am using 6173 stable release.

The Error I am getting when third person joins :
error