Hey Brian,
If, like you say, the Numpad also behaves weird, you might wanna look especially to the GPU driver(s).
I don’t have any experience with driver updaters, I am using Linux, which, nowadays handles updates a bit better than Windows
(And, I can recommend disabling GPU Subdivision in your Preferences > Viewport > Subdivision…although that shouldn’t make a difference in this case, as this model doesn’t use any Subdivision Surface Modifier (if I’m not mistaken), but can cause weird glitches in other situations, when you do use a Subsurf Modifier…)
