I work back and forth between several apps every day. So to speed up my process I usually option-click the desktop to hide any program. If that doesn't Photoshop is the only app that seems to have issues with this. I do this with all apps, including a few Adobe products, including but not limited to: PS, iNdd, Ai, and Acrobat. It used to be kind of a hit or miss thing. If I was just adamant that this function work I would just close PS and restart it. This no longer seems to work. It's hard to nail down the issue. I just recently updated "the holy trinity" (Photoshop, Illustrator & InDesign) and also updated to OS 10.13.3 High Sierra. Always have loved your products! Thanks in advance!