If your address appears on the Royal Mail website correctly ( it needs to be exact match , not even small errors ) but doesn’t appear on the DSL checker (the BTw site ) , then by completing the Openreach formwize there is nothing more to do until Openreach get back to you
OR will compare records and it’s simply an omission, they will correct it , so your address returns the same as your neighbours , or they will confirm no availability, but as stated previously that would be more likely if your address were in some way different to your neighbours.
If you are confident there is no difference in the way the copper pair service is provided to you and your neighbours then OR will probably just correct the incorrect data they hold.
If you wanted absolute confirmation , property served by 2.5inch duct 56 normally has evidence if it ( grey plastic covers etc ) on an exterior house wall , visible where the duct appears , search for images of these grey plastic parts , (BT ) connector bend 4 , capping 25 , cover 101a , if these plastic parts exist on the wall of your address it should be serviceable , however if for some reason you can not see these parts but they are on neighbouring property that may be an indication of why your address is not showing availability.
