Hi. If anyone is having trouble with these issues, try HOLDING the E key for a second or two. This toggles 'Erase with Current Brush.' In my case, my Gaomon tablet evidently defaults to this feature being active at startup - regardless of what I select in Black Ink's stylus settings.
Holding the E key once at startup fixes it.
I went through multiple driver updates, forum searches, and reinstalls trying to figure this out. Hopefully it helps someone like me (who doesn't read instructions very thouroughly.)
Peace out, Napoleon.