Welcome to this user forum for BT Retail phone and broadband customers.
I assume you are a BT Broadband customer?
"E" side cables do not usually go faulty, so its more likely to be the DP on the pole which is faulty.
'E' sides do go faulty...... There could be many reasons for it though.
There are many joints on route, from MDF to cab, and if there is pressure issue, they can go faulty easily. That can have a catastrophic effect - especially on lead cables.
Hi @SherlockPhones and thanks for posting.
Sorry you're having so many problems with the line etc. Have you spoken with anyone recently about this? Do you have an open / ongoing complaint?