Photoshop: CTRL+J no longer duplicates a layer. Setting CTRL+J as keyboard shortcut also doesn't work.

Up until recently, in Photoshop CC, I could use CTRL+J to duplicate a layer I had selected in the Layers panel. Now, CTRL+J does not do anything when pressed.

I tried going to Keyboard Shortcuts and setting CTRL+J as the shortcut for Layers > Duplicate Layer - and it does not add my shortcut. I can set it to most anything else, such as, SHIFT+CTRL+J - but CTRL+J isn't allowed to be added as a keyboard shortcut for anything and it doesn't even provide a warning about it conflicting with another shortcut, it just doesn't do anything when trying to add CTRL+J as a shortcut to a menu item.

CTRL+J is a widely used shortcut that seems to have been taken away in recent version of Photoshop CC 2017 with no way to add it back manually.

Please add this back as the default or allow users to add it manually.