I had the same problem as @noammaoz, and only noticed it in recent days. My setup:
Plex Media Server 220.127.116.1195 on OS X 10.9.5
Philips Smart TV
As updates 18.104.22.16895 and 22.214.171.12433 came within days of each other just this month, I had a feeling they were the cause of the problem. Thanks to a tip from @paulkeeley at this thread: https://forums.plex.tv/discussion/223300/osx-rollback-update I found a workaround to recover the "Content" folders of previous versions of Plex Media Server. So I tried rolling back to update 126.96.36.19985 (released Feb 10, 2017, I think?) which was around the last time I recall the setup working, and true enough, it did work! My TV is now able to detect the media server once again. \o/
So evidently, there may be some issue with 188.8.131.5295 (and 184.108.40.20633) that's causing this problem?