Recently worked on multiple occurrence of an issue with SRS V2. Where SRS joins a meeting for few seconds usually 1-2 seconds and then abruptly disconnects.
Generally it keeps on happening until device is rebooted but this is not seen to be done in all instances. Some times meeting join works with a reattempt.
If you are facing this issue would suggest to take logs from a Device. To take logs you may need to run Powershell Scripts as defined in below link.
And in UCC API logs of SRS, file name usually would be like SkypeRoom-Lync-0. Filter out session for failed attempt and if you see that BYE message is sent out by SRS with in few seconds after receiving 2ooOK .
And Diagnostic message in BYE is printed as
reason="Media session terminated on internal client error"
With ICE warning as ICEWarn=0x40400a or ICEWarn=0x404000
You could also fetch these details from monitoring reports as well.
It may be related to same issue where SRS application is actually becoming victim instead of causing issue. I observed form additional logs analysis that apparently it seems like SRS is failing while getting hold of network interface. And thus disconnects the call due to internal client error.
If you are observing same issue i would suggest to update OS on SRS surface device. In multiple cases where similar issue is observed updating Windows on Surface which in my case installed following KBs. Helped and resolved the issue.
You may need to open a ticket with Microsoft if even after updating OS you still face this issue.