Hi Daniel,

I solved it! In the tls.cfg file I changed 

method = TLSv1.2+ 

to 

method = TLSv1.2

It seems like Kamailio wasn't liking the TLS 1.3 connections. The documentation states it should work when using Open SSL 1.1.1 and I am indeed using that, so I'm not sure what went wrong. Could it be a bug?

openssl version -a
OpenSSL 1.1.1  11 Sep 2018

I'm happy I have the WSS working now. I will test the audio shortly and report back.

Thanks again for all your help,

C