on 26/12/2018, Broadback supposed :
I have had a BT2700 and a Mybelle 360 connected successfully for some time.
Now I wish to have a Bluetooth enabled phone so have purchased a Amplidect
400BT to replace the Mybelle. I seems they do not like each other. when both
are connected the BT 2700 refuses to answer calls, or indeed ring. what, if
anything, am I doing wrong? I thought one solution may be to purchase
additional handsets for the Amplidect, however I cannot find them anywhere!
:-(

Both distinct phone sets, need to be set to use one single common base
unit, rather than the two separate ones I assume you are using now.

The one(s) not working with their intended base, might be rather
restricted in their facilities, but should do the basic functions.