Certain keys (like most on the numeric keypad) do not work on the PC side, they work properly on MorphOS.

Any way to get them working on the PC side?

Not sure about those keys exactly, but the VNC protocol isn't able to map all keys in all situations.

I suspect it just might be some weirdness with 3.19 at this point.

Twinvnc worked perfectly on 3.17 (including numeric keypad, etc.) and now with 3.19 it sometimes won't type or uses hotkey commands when your just typing.