If you have spoken to BT and say ‘all is as is should be’ then the question for them is ‘ why isn’t it working then ?’ , it’s a false argument to say if you are not switching providers it’s straightforward, your previous service was on different system to the new service, and although it’s the same provider and same router it doesn’t mean that BT don’t have anything to do , they have to configure your access on the new system .
Openreach would fit the ONT irrespective of the ISP , but anything extra ?, if you were a customer of a small niche provider and the router that ISP had supplied was faulty , or hadn’t arrived by the time of the OR install , the OR tech can’t supply one themselves, and OR are not allowed to make extra efforts for BT customers , they have to deal with all ISP in an equivalent way, if BT ‘pay’ OR for a better level of service, but that level is available to any ISP willing to pay , that would be equivalent, but it’s not within OR gift to guarantee the ISP has done everything necessary for their customer to get on line.
I’d agree that if BT say that they will demonstrate it fully working then they have failed to deliver that , but presumably they should arrange a directly employed BT engineer for a managed install for this , not OR .
As you have been in contact with BT FTTP team , and they have supposedly checked your configuration and that the correct ONT serial number is registered against your service , what have they said they intend to do next ?, because sending OR back out could be pointless, but it’s possible the ONT ( which is OR responsibility ) is displaying the correct lights but could still be faulty , so getting a replacement fitted and it’s serial number registered may be worthwhile , but it’s unusual for a ONT to be faulty in this way , keep us advised.
