I built the entire distribution afresh, from the OpenUSD repo. usdview works, but spews these errors. Looking at the code, I see that QInputEvent does indeed not have a key() member function, but QKeyEvent does. So maybe this is a PySide6 issue?
What specific PySide and USD version are you using?
We use USD 24.5 with PySide 6.5 here and I haven’t seen that warning pop up, at least on a Mac.
USD 24.05, PySide 6.7.0. Doesn’t happen on the Mac, only on Linux. Very odd.