Recently Select and Mask stopped working properly when it had been running fine for weeks before. As far as I know, nothing changed with my hardware so I have no clue what the issue could be.
Basically, if I go back into Select and Mask after the mask is already created, it won't show me what's masked out even if I use overlay and have the opacity way down. It's very frustrating and really slows down my workflow, not to mention the brushes also lag extremely bad when using Select and Mask, and make it almost impossible to use. I had someone look at my computer and he found nothing wrong with it, the specs on my computer are above the minimum required, and I even tried lowering Photoshop's performance to basic but it didn't work. Does anybody else have this issue, or know what the cause could be?
I was having a similar issue and have been reading forums. Here's what worked for me: when you open "Select and Mask" look in the Properties. Make sure "Show Edge" is NOT checked. As soon as I did that, my selection showed. Took me a while to figure out, but that's what did it for me. Hope it helps you!