Man do I wish that Paul had responded. I’d read line by line thinking this is it… this is the solution!
I am having the identical issue (only from a Mac). It sounds crazy and is doing my head in having to go around in this eternal loop. I’m very technical, am new to NAS EX2 Ultra and have no plausible explanation.
The latest install file for EX2 Ultra being PlexMediaServer-22.214.171.1241-8bec0f76c-MyCloudEX2Ultra.bin sent me back int this loop.
Plex has no problem finding other servers on my home network. I’m following the instructions you posted about how to reset the Plex database - it’s taking forever…While I am waiting it’s worth nothing this is a second hand drive and I believe the previous owner used it for Plex. So if this solve’s it maybe this was the case for Paul too. Yes I did the 40 second factory reset prior too.
Anyway, it took nearly 3minutes ‘updating’ before I had to attempt uninstalling with run turned off. Second time round uninstalling it’s worked instantly. Have added the bin file manually and… no luck still.
There has to be some sort of compatibility issue between EX2 Ultra and Plex?