The call blocking mode is answerphone, they announce themselves, apparently, but then nothing happens. But they shouldn't be call blocked at all - they are in the phone book, and they get correctly identified when we look at previous calls.
Can you make sure that you have not set blocking for International calls.
If you have checked all of those settings, then it may be something within the incoming CLI, that is not being interpreted properly.
That would be what I see on my BT 4600.
Not sure why certain international numbers are not being directly connected in your case, but at least they can get through if they announce themselves. It may be something to do with the phone not recognizing that specific prefix.
You could ring the helpdesk number.
OK: in fact, they don't get through - they announce themselves, but the phone doesn't ring.
But I'll try the helpline. I strongly suspect a software bug - this has happened *sometimes* from Germany, and sometimes fromSwitzerland, but not always.
Going away for a few days now, but watch this space!