Quicktime corrupted

When I try to use Quicktime something awful happens. Multiple apps, like Adobe Bridge, open up and I can usually also see a QT window. But cursor is gone. Multiple windows continue to flash open and maybe close. One was a solid bright magenta. I then went through the following process several times. Forced shutdown, restarted, same windows come back up again. A couple times with the same result: multiple windows, no cursor. Once I was able to quickly get the cursor to move so I did a force quit on QT which allowed me to take control again.

Today before this started I was watching a video on a legit website. I had trouble getting it to run, but finally could but then I could not close it and noticed another QT window showing an mp4 file a friend sent me by email. The aberrant behavior began at that point.

Once I got control again as mentioned above, I deleted that email containing the suspect mp4 file attachment everywhere I could including deleted files. Tried running another small mp4 file in QT and the aberrant behavior started all over.

So I am stuck. Cannot use Quicktime. Also, dont know where copies of the mp4 file might reside as I certainly want to delete them.

MacBook Pro, Apple M1 Pro, 14.4.1

Talked to phone support she said all she could do was send me a link to self-help with a case number which she did. There must be better support than that???