I have a similar problem. The Chrome browser version ALWAYS finds NOTHING in a search, even for a movie, TV show or music that I know is in the database.
the Inspector Lynley series is clearly present in the database, but search finds nothing. For ANY search term.
But it will cast to Chromecast devices.
Whereas the desktop Mac app WILL find things in a search, but won’t see ANY Chromecast devices.
So both are broken in different ways.
AFAIK I have the latest versions of both server (which drives the Web client Version 4.87.2 of Plex) and desktop client ( Version 1.97.2.190-ca5000d0).
Any fixes available?
LATER
It seems I did NOT have the latest media server version, and when I updated it from v1.29 to 1.40 the Web client (now v 4.132.2 WILL search.
But the Mac app (which said it had updated itself the last two times I opened it) is stilll v1.97.2.190-ca5000d0 and still can’t see any Chromecast devices.