Strange behaviour in IndexArtwork

[Peter StreamMagic]

(25-04-2021 22:42)Peter StreamMagic Wrote:  

(25-04-2021 22:14)Peter StreamMagic Wrote:  

(25-04-2021 21:57)simoncn Wrote:  Do you have an unintended "new line" character in this tag value?

What do you mean by a "new line" character?

Somehow MP3 Tag doesn't show all tracks.
I looked for faulty tags using DBpoweramp and found one!

I was a bit overenthusiastic!
There is definite something wrong, but this counts for all tracks
    when hoovering the mouse
    after opening ID-tag

And now the question how to get rid of this issue?