Mouse function stays, I used it to exit the game. Nothing hangs or freezes the characters act like they would if you weren't doing anything. I don't own a controller and no other USB devices are attached. I do have a Bluetooth connection to some speakers but I wasn't using the speakers at the time.
Just tried the game there again and they keyboard didn't lock. It looks as though the problem is intermittent rather than permanent, although it did happen the first 2 or 3 times I booted it up.
Thanks for the help.