I use Proton vpn, and it takes a couple of tries just to load the files. Unfortunately though, I can only use MP3Tag with a vpn since a recent windows 10 update. It 'fails to authenticate' without a vpn and I can't find a fix anywhere. If there is one, I'd really appreciate it!
Can you explain what you mean by that? Are you referring to loading files when starting Mp3tag?
This sounds like using Tag Sources to me, can you provide details (e.g., a screenshot).
It seems as if the issues were caused by me using the portable version. I deleted it and tried the standard installation instead, now everything is working again. Thank you for such a great piece of software!