I've been using a cintiq for a while and have never had an issue like this. I'm not sure if it is Photoshop or the tablet. I'm using windows 10 and CC
I was suddenly not able to use the brush tool, when I touch the stylus to the tablet to draw it behaves like the space bar is held, just drags the image which ever way I'm trying to draw (still showing bush tool).
If I hold down the stylus for a second or two the ring appears and then i am able to draw. And suggestions would be appreciated, this is incredibly frustrating. Thanks!