I have an M720 mouse and a K780 keyboard. Flow is enabled for both. The keyboard is connected to one computer, in the first (F1) position, and to the other flow-enabled computer in the 3 (F3) position. When I am rebooting the 1st (F1) computer and start that with the keyboard connected to that computer, I am unable to manually change the keyboard connection to the other computer until the first computer has come back online. The mouse can be switched without issue. The mouse and keyboard are both connected to the first computer via Bluetooth. The Mouse is also connected to the second computer by Bluetooth and the keyboard by Logitech Unifying Receiver (because this seems to be the most stable and performant setup for me). I have been able to reconnect the keyboard to the second computer during this blackout period (while the first computer is rebooting, say) by putting the keyboard into pairing mode for the F3 button and repairing it to the other computer, but this is still annoying and should be corrected.