When I'm using my MBA at home I have it closed and connected to an external monitor along with Apple bluetooth keyboard, trackpad and mouse.
The monitor, keyboard, trackpad and mouse all work fine when I'm logged in, even if I lock my MBA I can enter the password to re-enter using the external bluetooth keyboard.
However if I do a cold boot or a reboot my external monitor remains connected and I get to the login screen however I am unable to login using any of the bluetooth devices. I have to open up my MBA and use the built in keyboard and trackpad to login. Once logged in I can close it and revert to using my bluetooth devices.
I recall it once worked fine when I only had one user account at login. I can't be sure but suspect it might have changed when I added an account for my partner so there's two logins at boot, but can't figure why this would affect it.
I've tried removing and re-adding all the bluetooth devices but no luck.
Any help appreciated.
MacBook Air (13-inch Mid 2012), iOS 9.3.5
