This also happened to me, and I’m embarrased to say it was my inattention that stopped me resolving it for over a fortnight!
Log into your MyCloud NAS then select Apps, on the left you’ll see a list under Installed Apps - select Plex Media Server this will bring up the following
App Name: Plex Media Server
Version: 1.41.8.9834
Installed on: Tuesday, 08 July 2025 12:49:32
App Settings: [CONFIGURE]
Run App: [ ON ] - [ OFF ]
Remove App: [ UNINSTALL ]
You will most likely find the ‘Run App’ has been toggled to OFF after the firmware update. Turn in back to ON and you’ll be back in business!
