How do you have photoshop set up?
Meaning are you using the Application Frame, Floating Document Windows or...?
Are you using Spaces?
What version of mac os, photoshop and lightroom are you using?
Maybe you can post a video of what's happening on You Tube so we can get a better idea of the possible problem.
Can't help but can confirm I have the same problem intermittently. Just happened, hence my search finding this thread. I'm on Sierra, Mid 2010 Mac Pro, 64GB ram. I have Chrome and Cinema 4D open and a large 14Gb file open in Photoshop. I alt-click on Cinema 4D to switch over while hiding Photoshop but hopping back only gives me the title bar. If I cmd-o I get the window to open a file but once opened, that doesn't show up either. I can Save As successfully and quit but nothing seems to make the workspace show. I also tried switching workspaces to see if that would jolt it back to life but nothing worked.
Having the same issue. If I hide the Photoshop app and try to come back, the Photoshop windows, documents and panels no longer show up. The menus at the top of the screen appear, and keyboard commands work, can open window dialog boxes, but nothing in the Photoshop app appears. Can switch into or unhide other open CC apps, like Illustrator, but Photoshop requires a quit and restart to restore function. It happens intermittently, twice in the past month.