Home phone only rings once or twice when anyone calls. BT has tested the line and no fault found. Have tried a different handset and the problem remains. Making outbound calls is no problem. I think that the call is connecting automatically after one or two rings. Guess the problem is somewhere in the internal wiring?
Have you tried it on the test socket?
have you uinplugged all broadband equipment and filters, extensions, so you just have the BT master socket with a phone on it.
also with no phones plugged in what happens?
Just because BT can't 'see' a problem, doesn't mean there isn't a problem.
If your socket faceplate has a 'panel gap' across its face, undo the two screws and remove the front half of the socket, there is another socket there. Plug in a previously unused or a neighbours phone without using a broadband filter, and try ringing it.
When it rings and stops, if you pick up immediately is anyone there? If yes, then it is probably a fault. If no, you've got some prankster playing you around.
Does it ring and then stop ringing but the incoming call is still there? Or does it ring and cut off, dropping the call?
Have you tried using a different phone?
is your fax machine picking up the call 😉
* not helpful i know but i rememebr the 80s/early 90s vaguely watching my parents trying to beat the business fax to the call. 😉
Have you tested with the phone plugged into another socket? Broadband etc. all working OK?