Your local exchange has been ‘digital’ for 35+ years , the digital exchange program was mainly completed during the 1980’s , so when you stated your line is ‘apparently now digital’ the assumption was that you must have meant you were on Digital Voice , but if your phone isn’t connected to your router then it isn’t DV.
If you still are on PSTN ( as seems likely ) and the dialtone continues after you have dialled the number ( you can ‘hear’ your handset making ‘tones’ ( DTMF ) as you enter the phone number ) , it’s an exchange fault , ( not that uncommon ) , the DTMF receiver in the line card not responding to the tones sent , if coincidentally you were advised that you were being converting to DV , it would actually solve the issue but as presumably you are not yet being migrated, you need to report it ….FWIW , a line test will not pick up this type of fault as the ‘line’ ( the copper pair ) is not the problem it’s the exchange equipment your line is connected to , it’s actually not Openreach that look after exchanges , chances are your physical ‘line’ will be moved to a different exchange line card that’s working OK , the Openreach engineer will rejumper your line on the exchange MDF , but obviously to get that arranged BT need to submit a fault report .
