Thanks a lot for reporting this Randy. Just yesterday another user reported the same – also with a Huion. So it seems we need to investigate and get something fixed.
In the meantime, it seems this workaround should work for you too:
Find the file βqt.confβ (probably here C:\Program Files\Animation Paper\qt.conf). Delete it or rename it (to save it). Then launch Animation Paper again.
This will force Animation Paper to use Windows Ink β which should give you pressure sensitivity.
Please let me know if this helps.
Thanks,
Niels