I use a Wacom tablet for everything in Photoshop. I constantly use the Select and mask screen to make refinements to selections when cutting products off white backgrounds. The latest update (21.1) crashes consistently when using the brush tool and the zoom is accidentally touched on the pen. I have to force quit Photoshop and restart with all of the selection I was carefully cutting out lost. When I roll back to previous versions the problem is not occurring. I'm on a late 2013 Mac Pro running Mojave 10.14.6. All drivers and operating systems are up to date.