Running Mp3Gain album analysis makes mp3 tags disappear in Mp3tag only

[LyricsLover]

Maybe this thread can help you?

APE tag hides ID3 tag

You can't. In MP3tag APE tags are displayed if present and selected to be read and all other tags are not displayed. This is also documented: The workaround would be to use a replaygain program that writes the data to ID3 tags instead of APE tags. Or use a program that copies the contents of ID3 tags to APE tags when creating new fields.

Including the linked documentation part:

Mpeg

These configuration options are affecting audio formats which are using ID3v2 tags (currently MP3 and TTA).

Read

The order below, is the order in which Mp3tag reads different tag formats (that means that displaying APEv2 tags is prioritized over displaying ID3v1 tags). Mp3tag only displays the contents of one tag format at a time. The read tag format is denoted in the Tag column of the File List.