Fixed mine by adjusting the below items. In my case, it seems related to prosody having updated at the same time as jigasi. I assumed it was a jigasi issue, but I think this is related to certs becoming invalid after prosody updates.
replace =localhost your domain to the line below
- /etc/jitsi/jicofo/sip-communicator.properties (add the line below)
- sudo systemctl restart jitsi-videobridge2
- sudo systemctl restart jicofo