So I put my computer to sleep two nights ago after working on it all day with no issues. Woke it up yesterday afternoon to do some more work, and I was unable to login at the lock screen. Fine, I thought – give it a few minutes, I know it can be unresponsive when waking from sleep. After keeping the machine awake using the trackpad (yeah, that was working) and still being unable to type after about 5 minutes, I decided to reboot the machine. Power cycle happened normally, and up comes the (file vault enabled) login as normal. Click on my face, go to login, nothing happens when I press keys! I didn't have a spare USB keyboard with me yesterday, but I'm back in the office today with one, connected through the USB->USB-C adapter, and it's working okay. The internal keyboard will now type a few random letters when I press anything - usually xxxxxxxxcxxx or, you know, some weird combination. Strange part, I can't seem to get the machine to boot to Apple Diagnostics? (d). It'll boot recovery, and the keyboard issues persist - in both recovery, a normal session (after using a usb keyboard for login) and guest mode. Is it normal to not be able to use an external keyboard to boot to Apple Diagnostics? Has anyone else had weird keyboard issues, for seemingly no reason? I've gone through the online support steps, and had a conversation with an Apple tech - who just did the same things I did. Now have a Genius Bar appointment for the end of next week (no other appointments!).