R1 = Repeater mode. I've turned that off via the menu The crossed out handset symbol is now also gone. The phone is still beeping. It does a double beep every few seconds. The battery seems to to charged. I've switched batteries with another phone and the beeping continues.
We have several EnGenius Durafon Pros (model SP-922PRO HC V2). One of the phones is now beeping every few seconds. On the display, an "R1" is shown as well as a symbol of a handset crossed out. I've tried unregistering/reregistering the phone, but this didn't help.