same problem on my side with video calls and screen sharing. I tested a lot of versions and discovered this bug with in nightly version 22.214.171.124. Version 126.96.36.199 is still working good, but later versions do not. Latest nightly 2.6, 2.5 and latest stable 2.6 are affected as well. Please check what have you changed between 188.8.131.52 and 184.108.40.206. I like Jitsi, but this is big issue.
Tested on SIP (Elastix 2.4) and Xmpp (Openfire 3.10.0) internal servers. I am using jitsi on windows 7 SP1, but mac users reported same problems (not sure which version). I could not find something strange in Jitsi logs, but there are logs attached from 220.127.116.11 and 18.104.22.168 versions.
logs.zip (51.2 KB)