One artist being sorted by last name

[simoncn]

When you refer to "search", do you mean a search from your control point or are you opening the AlbumArtistSort and ArtistSort indexes and browsing their contents? The latter is what you need to do.

The other thing you can do is to set the writeAllTags property and do a rescan. This will write a complete list of all tag values in your library to a file that you have specified. You can then look at this file and see what AlbumArtistSort and ArtistSort values are present in your library.