When using Siri to play a track or album using Plexamp, it generally decides to play an unrelated track or album by the same Artist. It seems to be biased towards offline items, which tend to find very loose match and plays that.
Log example:
“Hey Siri, play Since You Been Gone by Rainbow”
Mar 31, 2023 17:38:04.648 [Javascript] INFO - Player: Processing voice play playNext: false, shuffle: false, addToQueue: false, nowPlaying: false, similar: false, artist: Rainbow, query: Since You Been Gone, metadataType: -1.
Mar 31, 2023 17:38:04.648 [Javascript] INFO - Player: voice play matched offline item Rainbow / Bent Out of Shape.
In that example, “Bent Out of Shape” is an album by the same artist that I had downloaded for offline play; it does not contain the track that I requested.