If there is an error on the address database then your current provider ( Shell ) need to advise Openreach via an ORDI request to align the address information with what is held by the Royal Mail , that should allow other ISP to locate your address correctly and initiate the migration process , however , presumably at some point Shell ( in the past ) managed to navigate around the address an anomaly, and raised an order to get you provided with FTTC , migrating from another ISP , , there is no reason why an alternative ISP cannot also identify the appropriate address and arrange a migration, provided you interact with them in the appropriate way .
Obviously if you feel the address data should be correct , ( and it should be ) it’s Shell that need to arrange this via Openreach with the ORDI request ( Openreach Data Integrity )
FWIW , your phone number , unless provided by BTw is not going to a provide result on the BTw checker and Shell are not BTw
Edited by Iniltous (Thu 21-Mar-24 17:13:59)