I've been using Google Music from the beginning, so I have a lot of experience with it. For some reason, the last time I added a few new albums to my music collection, Music Manager acted like the 12k songs I already had in the cloud weren't there anymore. So, it went through an upload of everything (there was more to that issue, but I digress). Now, when I "shuffle all" of my songs to Chromecast, it stops occasionally and says it can't play sideloaded songs remotely. Well, why did it add it to the queue then!?!

I don't know why those songs aren't in the cloud, except that it is looking for the older version before Music Manager decided to go blank and re-ingest everything (before that, everything was in the cloud - some of it, I pinned to download on the phone). Does anyone know how I can get it to forget the sideloaded songs - like deleting them from the phone?

This is such a mess.