Jitsi does check the SAN. Can you take a look at the logs
(https://jitsi.org/logs) to see why validation fails exactly?
I got the log file from Marcel privately:
"unable to find valid certification path to requested target"
So, Marcel, the certificate used by your server couldn't be validated to a trusted CA. If it is self-signed or from your company, then this is normal. You have to accept the warning or select the checkbox that you always want to trust it.
If it is from an well-known CA, then your server might be incorrectly configured and doesn't send all intermediate certificates. Otherwise the CA is not well-known enough for Java 1.8.40.
The protocol part of the srv is left out because of an rfc that says so.
Don't know which one out of my head.
Dane will be coming sometime this year (hopefully I'll find the time).