Pen keeps opening menu instead of drawing, help?

I’m working on a test animation to see if buying Harmony is going to work for me- I think it will, but I’m having a small bug/difficulty currently.
When I’m drawing with pencil, eraser, or paintbrush, my tablet pen keeps trying to open a dropdown menu, and won’t draw an actual line. Is this a bug, or just my tablet? (I have a Huion tablet and pen)
At least, is there an option somewhere to disable the pen from opening the menu thing?
Thanks in advance!

You can like the pen is so tough you need to put a lot of pressure to start drawing. On the other hand, you can feel the pen is soft that touching it simply with the tablet would make it start drawing. Online Class Help