also this problem just occurred a couple of minutes ago on my machine. i clicked on the photoshop icon at the bottom of the screen in the taskbar, hit the ctrl / alt / shift keys a couple of times and clicked in unreal again and my keys STILL didn’t work.
so again i clicked on the photoshop icon in the taskbar, then this time i moved photoshop to my main monitor, clicked in the center of the app, then hit the ctrl/alt/shift keys again and went back to unreal and this time it fixed it.
why? i don’t truly see the difference… maybe you have to click in photoshop? or maybe it has to be on the same monitor? or maybe i didn’t hit the right combo of the ctrl/alt/shift hotkeys? not sure.