watercolor brush doesn't work

[禹璇林52486451]

I dowload Kyle's watercolor brush and use the same brush he used in his tutorial, but there is no color coming out of the brush. I have delete the brush set and reload it, and also relunch Photoshop but still doesn't work. Does any body know what is wrong?

[禹璇林52486451]

I use a wacom cintiq16 btw.

[禹璇林52486451]

If I use the touch bar on my computer there's color coming out of it but if I use wacom pen then it gets nothing.

Is it something to do with the wacom system?