I always refused to use a bluetooth connected keyboard for my private work because I don’t trust a bluetooth connection to be secure. Also the necessary charging of the device’s battery is something I don’t like. A keyboard has to “be simply there” and to work under any circumstance.
Today I got my opinion supported by accident.
When I turned on my company laptop the keyboard did not work. With the laptop’s keyboard I logged in and tried to find out what happens. I saw the keyboard but it disconnected very often.
Also the power level was odd - last week I charged the battery, so missing power would mean that the keyboard’s battery collapsed. But this was unlikely because the displayed charging level was at 53%.
Finally I disconnected the keyboard through the bluetooth settings (Forget device) and reconnected my keyboard. It showed 91% battery charge.
So when turning on my laptop it connected to my neighbours keyboard (through the wall). This should never happen if a "known" keyboard was already connected.
Implications: If the situation were reversed (my keyboard connected to the neighbours computer) then I would have typed my password into an application there. Nothing I would like to have happen.
Now I renamed my keyboard and mouse in the bluetooth settings so I can see that a different device is connected. At least this speeds up troubleshooting.