First of all, thank you for the detailed answer. I'll test your version later, but for now the way I'm used to it and how it worked until Kodi 20.3.
The only thing I'm missing under music videos is artist images, for which I don't have any data (CDs) under music (see Achim Reichel).
For the artists for whom I have music data, the artist information (such as biography, folder, fanart, clearlogo) is automatically added to the
music video artists (see Led Zeppelin).
Now I can't insert a biography fanart or clear logo for video artists for which I don't have music data, but if I select the corresponding artist (Achim Reichel) and open the context menu, select the menu item "set artist thumb". This also works in the faulty version. I can then go to Select and then navigate to the folder that also contains the music video. I put a picture of the artist in this folder. I can then select that too. Unfortunately, the image is not adopted, but the empty placeholder remains.
I noticed a peculiarity. I use the German language. The incorrect version contains the English term “browse”, while the working version (kodi 20.3) contains the German term “Auswählen”
Many thanks for your help