JVB is not working when there are more than 3 users in an room

Hi everyone, I have been trying to installing Jitsi meet on Ubuntu 18.04, everything works fine when there are only 2 users in a room, but when someone else joins, no one can hear or speak.

Jitsi is installed on Google Clouds, computing engine

Some of the problems we see in the Chrome console are ‘Channel closed: 1006’

Check your firewall; make sure required ports are open and accessible. Check port 10000/UDP especially - make sure it’s open and properly forwarded, if behind a NAT. Make sure there are no host firewalls.

WhatsApp Image 2021-04-21 at 12.02.01 AM

I already do that but still not working