import mp3 file is corrupted

[Tiboy]

Hello Community!

I have something very strange going on here. Since updating to 2021.3.1, import audio (or drag & Drop) doesn't work anymore. The files are abruptly cut off at the end. Approximately 5 seconds, more or less. The longer the file, the more is cut off at the end. Sometimes, when importing, the file is stuttering too at the beginning. It also happens, when bouncing something to mp3 and importing back to the same or a brandnew session. I tried to go back to 2020.3., and it's the same. I trashed preferences, workspace without success. I reinstalled without success. Preferences are "Copy files on import" & "convert files to session format". Delay Compensation is activated. In never changed anything. The strange thing is, when i listen back to the (bounced or original) file in the finder, everything is normal. I also imported the files to LUNA (the UA DAW), and everything works there as it should.

Edit: Also when importing via the "import Audio" Dialog, the size of the file is not the same, as can be seen in the attached pictures. This also happens to wav. files, but wav files are imported correctly without any cut offs. It doesn't make any differece when the "Apply SRC" Box is checked or unchecked...
Has anybody an idea, what's going in here?
I'm on Mac OSX Catalina 10.15.7, MacBook Pro Retina 11,3, 2,8 Ghz i7, 16 GB Ram. Apollo Twin X

[Tiboy]

Nobody?? Sent an Avid Support Ticket, no answer till now.
I can’t believe, I’m the only one on planet earth which has this error...
I googled and searched my ass off with no luck ☹️