In Photoshop CC 2018 the brush selection UI is really unresponsive. Previously Photoshop versions I could open the Brush tool with my Wacom pen button and select a brush without hardly looking at the brush palette and it would select it always. Now, very often it doesnt actually select it. I would say almost half the time I click a brush (I have the small brush tip icon look) it doesn't change. This causes huge issues for a painting workflow and I end up having to paint undo all the time or take a closer look that I actually get the new brush before starting to paint.