App not connecting

Hi

Installed Jitsi on Kali Server.
It works form Computers with Chrome Browser.
Let’s encrypt is working. No Security warning wenn connecting from outside with jitsi.mydomain.ch.

Android app ist not connecting. (iPhone not available)
Server is behind haproxy.
Also tried to expose Jitsi server by DMZ.
Under /etc/jitsi/sip-communicator.properties
org.ice4j.ice.harvest.NAT_HARVESTER_LOCAL_ADDRESS=192.168.1.210
org.ice4j.ice.harvest.NAT_HARVESTER_PUBLIC_ADDRESS=my Public IP

Any hints where to search, which Logs could be helpful? Don’t get any help from var/log/jitsi

Thankfull for any help
Davide

I checked with digicert.
Everything passed eccept:

TLS Certificate is not trusted

The certificate is not signed by a trusted authority (checking against Mozilla’s root store). If you bought the certificate from a trusted authority, you probably just need to install one or more Intermediate certificates. Contact your certificate provider for assistance doing this for your server platform.

Because it is a Let’sEncrypt, i think should be ok?

Tested with iPhone, it works

nobody some hints? idea where to search?
Only android is not working.
Tested with V8.0 and 9.0