Best answer by Tim_OVO
The two meters might struggle to communicate if there's a big gap between them, especially with thick walls. Generally I’d say anything under 15 meters is fine, but we do have a little gadget called a 'relay' that can help with signal issues like this. I'd suggest booking it in and waiting for the engineer to advise you on site.
So that I can move this topic to an existing thread, can you tell me if you're a Pay monthly or a Pay as you go customer? That way, other users can find this query more easily.