Actually it is, as the post above me has pointed out if you leave the Gwent option on it will screw with the inventory until you restart the game and trainer.
Tested it numerous times, and can confirm it does.
Can you explain me how you solved your issue ? I have the same problem : all the slots in my inventory seems to be empty except for the gloves and so my game crash when there is a cutscene where my weapons are taken off.
I deactivate the gwent cheat, restart my game, restart my computer but my inventory always appears to be empty even if it is not.
Whelp, that answered my question!