Photoshop will become unresponsive after switching to another program for a brief period and then returning to Photoshop. Won't be able to draw/pan canvas everything is just frozen for a period until it does its thing and wakes up again. Sometimes this will result in several strokes then flooding your canvas from the clicking you were doing while it was hanging and trying to wake back up. Is this some kind of memory issue? This bug has been happening since 2017 CC.