Genre changed without checked checkbox

When I search for track information on Discogs and apply them the conten of the "Genre" field gets lost pretty often. This happens when the checkbox is unchecked.
When I don't pay attention to this it happens that all the Genre information is replaced by i.e. Electronic.
Does anyone have the same problem or a way to get rid of this behaviour?

Hi and welcome!

I'm not sure if I understand 100% but will try to explain. The Tag Sources feature currently works as follows:

  1. If you have one of the fields checked, e.g., Genre, Mp3tag will write the field contents to the tag of the selected files.
  2. If you have one of the fields unchecked, Mp3tag won't write this field to the tag of the selected files.

That is, there is currently no way of merging both the Tag Sources result and the existing field contents. From what I understand, you'd prefer the feature to do exactly this, where Tag Source search results take precedence over the existing field contents. Correct?