Is the terrace 6 dwellings , No2-No12 ( even numbers ) all served overhead from telegraph poles , ( I ask because sometimes terrace properties are fed from wall block or blocks on the end of terrace property, so the middle of the terrace need wiring that has to cross neighbouring dwellings walls ( that can cause problems with permission ) I’ll assume all dwellings in the terrace are served from poles and not wall blocks, perhaps you can confirm this .
It’s not likely that by design this terrace was split across two PON areas , but it’s possible that a quirk of the way previous copper service was delivered has left No12 in reach of a PON that doesn’t reach to your address , a PON ( passive optical network ) is normally designed to accommodate a certain area , constrained by the existing Openreach infrastructure, the borders of a PON sometimes seem strange because you can have near neighbours on either side of the boundary so one can get FTTP and the other outside that boundary cannot .
Obviously I don’t know how your address and neighbours are situated, but if for example , all the terrace faced the same road ( and are known by that road name ) but No12 was an ‘end terrace’ as estate agents would describe, and on a road T junction so the side aspect of No12 faced a second road , that all the others in the terrace don’t have , and it happens that in the past No12 overhead service was from a pole in that other road ( so basically No12 has two poles that could provide service, one pole in the same road as No2 -No10 , and an alternative pole at the side or rear of No12 on a different road ) , and if that alternate pole is in an ‘live’ upgraded area , then this historical quirk could mean that only No12 has FTTP access when No2 -No10 don’t, yet they are all on the same terrace.
Obviously this may not be the case with you , and your situation is nothing like that , and it’s just you at No6 excluded yet No4 and No8 have availability in which case it couldn’t be a scenario similar to what I have described.
Maybe take a look at No12 ( if it the only one with availability ) and see if it’s overhead wire is from the same pole as the wire to you at No 6, it may even be that No12 has two wires one on the front and one on the side/rear to a different pole to you , hence it’s FTTP availability.
Sorry for the lengthy post , a picture is worth a thousand words ,
