Can you just test without expressions? That would let us know. If that's the cause, share the expressions you're using. Thanks.
Sorry I don't know how to do that because the expressions are central to how the whole thing works.
I have not changed these expressions for about 5 years. They've worked perfectly for many versions of MC until 28.0.73. And they still work with 28.0.73, just 10 times slower.
Here are the expressions I use for my paths:
Audio Path: Audio\ifelse(isequal([Filename (path)],Audiobook,8),Audiobook\[Artist] - [Album],isequal([Filename (path)],Comedy,8),Comedy\[Artist] - [Album],isequal([Filename (path)],Course,8),Course\[Artist] - [Album],isequal([Type],Single,8),Music\[Artist Filename] - [Year] - [Album],isequal([Type],Various,8),Music\$Various Artists - [Album],isequal([Filename (path)],Podcast,8),Podcast\[Artist] - [Name],isequal([Filename (path)],RadioPlay,8),RadioPlay\[Artist] - [Album],1,Other\[Artist] - [Album])\
Video Path: ifelse(isequal([Filename (path)],Documentary,8),ifelse(isequal([Album],[Name],1),Video\Documentary,1,Video\Documentary\[Album] - [Year]),isequal([Filename (path)],Course,8),ifelse(isequal([Album],[Name],1),Video\Course,1,Video\Course\[Artist] - [Album]),isequal([Filename (path)],Podcast,8),ifelse(isequal([Artist],[Album],1),Video\Podcast,1,Video\Podcast\[Artist] - [Album]),isequal([Genre],Movie,1),Video\Movie,isequal([Genre],TV,1),Video\TV\[Series],isequal([Filename (path)],Music /(video/),8),Video\Music,isequal([Genre],MyImage,1),Memories,1,Video\Other\[Artist] - [Album])\
Images Path: ifelse(isequal([Genre],MyImage,1),Memories,1,Photos)\
Data Path: Documents\ifelse(isequal([Filename (path)],Book,8),Replace(RemoveLeft([Filename (path)],10),_,\),isequal([Filename (path)],Magazine,8),Magazine,isequal([Filename (path)],Paper,8),Replace(RemoveLeft([Filename (path)],10),_,\),isequal([Filename (path)],Podcast,8),Podcast,isequal([Filename (path)],Course,8),Course,1,Other)\