Running JITSI behind a firewall

I have gone through Jitsi Quick Install and set up the software on a Ubuntu virtual machine.
My virtual machine itself is behind a Firewall which also acts as a NAT and I can only use port forwarding to get to the any VMs behind the NAT.
I have forwarded ports 40443 on NAT to 443, 40080 to 80 and 40000 to 10000.
In addition I have set up Lets Encrypt certificates.
I have also changed the sip-communicator.properties and restarted services per suggesting in the Quick Install manual.

When I open up mydomain using port 40443 the Jitsi conference page opens up as expected.
I can start a conference but when I start the conference, it keeps disconnecting after every 30 seconds.

In the browser console I see following logs error logs in attempting to connect to https://myDomain/http-bind. Note In this request it does not use the port 40443
2020-05-03T09:29:07.107Z [JitsiMeetJS.js] : UnhandledError: null Script: null Line: null Column: null StackTrace: Error: “Strophe: request id 1.1 error 0 happened”
log strophe.util.js:89
error strophe.umd.js:1392
_onRequestStateChange strophe.umd.js:5017
Logger.js:154:22
2020-05-03T09:29:07.108Z [modules/xmpp/strophe.util.js] <t.a/r.Strophe.log>: Strophe: request id 1.1 error 0 happened Logger.js:154:22
2020-05-03T09:29:07.109Z [modules/xmpp/strophe.util.js] <t.a/r.Strophe.log>: Strophe: request errored, status: 0, number of errors: 1

Any ideas how to fix this ?