There are a lot of threads that deal with a missing context menu in W11.
I would save the configuration with the program internal functions in the file menu.
Then I would save the configuration in a safe location.
Then de-install MP3tag completely - if that was 32 bit version previously, then it could be that you als have to install that version again only to de-install it in a second run. This also applies if you want to switch from the 32- to the 64-bit version.
Please see also