SUMMARY
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***
1.
In the Tag 2 field, when I select multiple ID3v2.4.0 fields that I want to remove, and I press "delete", it does not delete them all at once. It deletes only one field, even though multiple boxes are ticked. I need to press "delete" multiple times before all fields are gone.

2.
When I select multiple tracks and I select multiple fields I want to delete (mostly only 1 song in the folder has the unwanted fields, the rest of the songs don't have these fields, but it is easier for me to select all tracks of the CD), the same happens but it also deselects the fields I want to delete after I press delete the first time. 

Even though the tick boxes disappear right after clicking delete, when I press delete again, it does delete the field that now looks grey (so I guess that field is selected even though the tick box is unticked).