It seems like you have a "file association" issue - probably due to running win 10 in compatibility mode. There surely is a way to do this in win 10 compatibility mode.
In95, 98, XP you could set the default program that opens when clicking on a particular file type i.e. "WRK", "BUN" etc.
If you can answer that question, it might provide a solution.
Good Luck - PS - I like Pro Audio too....It never tried to be a pro tools clone.