I have the latest Magic Keyboard (the one with a switch, not a button) and a 2018 iMac.
Today after lunch, the keyboard Magically stopped doing anything. Here’s what I checked:
- Battery was not low, I charged it yesterday and checked the batter was full yesterday.
- Keyboard worked fine before lunch.
- No coffee spill.
- No kids or other bad actors in the room.
- Tried plugging in and unplugging the charging cable.
- Tried changing the charging cable to a different port on the iMac.
Afraid to restart because then I can’t type in the password.
To reset your keyboard:
Hold down the Shift and Option keys (‘Alt’ on some keyboards) and at the same time click on the Bluetooth icon in the menu bar. Once the menu is showing, release the keys. From the Bluetooth menu, choose Debug > Remove All Devices. Reboot your Mac, then setup your keyboard and/or mouse as normal.