The activity feed

The feed is built in four card families, each answering a different question.

Card family	Means
Added	Entered your library in this window — the whole library, not just yours
Discoveries	Played for the first time ever in this window
Activity	Your own wishlist and favourite changes
Trending	Most-played in this window

Added is not discoveries

This is the distinction the feed exists to make.

Added keys off when the album entered your library. Discoveries keys off the first time it was ever played — so an album you have owned for three years and finally listened to last week is a discovery, and not an addition.

Added uses the source's timestamp

An album's "added" date comes from Plex's own record of when it entered the library, not from when Media first saw it.

That means re-importing does not make an album new again, which is the behaviour you want — a library rescan would otherwise flood the feed with everything you own.

It also means a wrong timestamp in Plex is not fixable from here.

Scope: me or everyone

Discoveries can be scoped to you or to the whole instance. On a shared instance those are very different feeds, and the scope control is worth noticing.

Your discoveries require a scrobble link — without one Media has play history but no way to tell that it is yours.