Another surefire way to test it would be to try it in another x32.
If you don’t know anyone who owns another one, Here are 2 companies in Australia that will rent you one:
If it ended up being the X32 with the problem, Behringer’s 3 year warranty coverage is outstanding. You’d have to ship it to a local repair facility, but I’ve found them to be quite fast. In the US at least.