BT have no different access into Openreach than any other communication provider and there isn’t really an avenue for an ISP to query an address shown as having no FTTP availablity, but the information that assessment is based on , is likely to be incorrect.
https://www.openreach.com/forms/fibre-broadband-availability---customer-form
It probable that you have already been down this route , but fill in this formwize, referencing that your immediate neighbours can order FTTP , and although you are served from the same distribution point , you cannot order FTTP , failing that , contacting the executive level complaints people may get the matter looked at , that’s assuming that your assessment is correct and you do have FTTP available and it’s a records issue .
If there is anything out of the ordinary about your address , like it’s known by a house name rather than a number , or has a suffix like No.1A , these anomalies can cause issues, normally that would be worth raising an ORDI ( Openreach data integrity) with BT ( if BT are your provider ) to check OR records align with the Royal Mail entry for your address , something the Mods on here used to do ( it seems that’s no longer the case ) , the other thing to try is use your UPRN instead of the postal address with the DSL checker, to see if the return changes or stays the same .
