The extended tags show that the data is really like that in the files.
So it is not only a problem of the display, but of the data.
So which program outside MP3tag writes to the files and resets track number and discnumber?
Or: which steps have you taken in the time between the old numbers and the new ones?
What happens if you use the track numbering wizard Ctrl-K and set new track numbers?
We can see in your screenshot that you also have added MUSICBRAINZ_ fields.
This only happens, if you tag your files with one of the MB websource scripts or if you use the official MusicBrainz tagger called "Picard".
Which one did you use?
And BTW:
What kind of music format do you use in the above case?
mp3? FLAC? mp4? Other?
I do not use any other prg than Mp3tag to change and handle the files. All the prgs just read them (foobar & vlc).
If I Ctrl+K the files they get renumber just like:
1
2
3
4 and so on
I have thousand of files and I can not Ctrl+K each CD/LP but the filenames are like 01. title.mp3.
Is it possible to copy the first two digits of the filename and copy them to the track field ?