I have. I was (coincidentally?) sending a link from my iPhone by Airdrop. The screen went black. I had to force-reboot. The computer seemed to take a long time

I have. I was (coincidentally?) sending a link from my iPhone by Airdrop. The screen went black. I had to force-reboot. The computer seemed to take a long time to boot after the password prompt, and then restarted. I made a mistake at the second password prompt, and it took minutes to try again. Third time's the charm, touch wood.