No, this is not the case with my speakers. When I switch them to line-in with the remote control, I can no longer find them with any Bluetooth device.

However, I did have them permanently on Bluetooth for a short time at the beginning, which a former flatmate fed him early in the morning to his amusement with Schnischnaschappi.
On the right side of a speaker, it has an LED that clearly lights up blue or green and indicates the mode.