It's been a long time since I've used it for a portrait where I had everything working before. The Watercolor brushing is not working well. It stops suddenly. The brush starts out like a very thin line and then jumps to the wide setting I had set it at. I tried varying my speed of making the stroke. I just sort of lost the knack since the last time I did this only a few months back. I'm also finding the airbrush also has this problem with starting out super thin and then jumping to the proper width.

I have the latest version of AR.
The Cintiq seems to be working fine in other apps.
The computer is a very fast, fairly new PC (all hardware and software and driver is the same as I used on the other painting where it was working fine).

Any suggestions?