Songs deleted from iTunes playlists after activating iTunes Match

I just renewed my iTunes Match subscription and now suddenly a big chunk of my playlists are all missing songs, and a couple playlists have been duplicated but with fewer songs! They're still available in iTunes but with the cloud symbol next to them has an x on it, and the little note that pops up when I hover over it says that the track was removed from iCloud. And when I try to add them back to the playlists I get a message saying "iCloud Music Library playlists can only contain songs from your iCloud Music Library. If you continue, [name of playlist] will be removed from your iCloud Music library and will only be available on this computer."

I don't remember this happening the last time I was using iTunes Match. How do I get my playlists back the way they were? And why did this happen in the first place?