iMac (Retina 4K, 21.5-inch, Late 2015)
3.3 GHz Quad-Core Intel Core i7
16 GB 1867 MHz DDR3
Apple Wireless keyboard and mouse.
Big Sur latest. Booting from external T5.
I turned on FileVault on the external T5 (many hours to complete). When I rebooted the machine the keyboard and mouse were not connected so there was no way to choose a user or type a password. No ‘default’ user was selected and no password entry box appeared. I had to plug in the keyboard and use a USB dongle wireless mouse and hard reboot to get the machine up and running.
I turned off FileVault and (many hours later) the bootup problem resolved.
I’m assuming there’s some problem in the sequence of events that won’t check Bluetooth before a user/password is entered when FileVault is enabled, but I’m guessing someone here knows more about this.
Any ideas? If I install Monterey will the same problem persist? (I’d rather not spend the many hours turning FileVault on/off to experiment, but that’s my next step if no one here has any insight into the issue.)