Hello - I was having similar problems, and then I saw this thread, on having Roon create a fresh database: Long delays (up to 10 - 30 seconds) for loading albums or start playing tracks (both local and Qobuz) - Support - Roon Labs Community
I followed the directions at that thread, and while I have lost favorites, tags, etc., my system has not worked this well in a long time. Previously, and since the last big update, I had had dropouts and multi-second delays when starting a playlist and between tracks.
I am hopeful Roon will provide some guidance of somehow restoring favorites, but starting with a fresh database is a night and day difference.