PS Layer shows my original Lyr while also showing my changes. Updates after hiding a layer only. ?

I'm on a Mac running Photoshop. After one of the updates (not sure what version), I started noticing that when I edit a layer, it shows that change but also shows my original (visually merged with my old layer content). It does this until I hide and show another layer below it and then shows my correct layer change. It's as of it's maybe a preview/ram/memory issue. Sort of like lagging?  This is not occasioally. It's every time I'm working in PS.

Any thoughts?