It wasn’t exactly smooth sailing at re-signing up, but Starling were prompt in their reply and at fixing the situation.
The 12-month closure ‘ban’ ended yesterday so I went to try and sign up yesterday and then again this morning and my mobile number was still attached to my old ‘closed’ account as it would try to log me in and then reject me as it had been blocked.
Emailed customer services to state that they needed to release my mobile number as my 12-months were over.
This evening, I resigned up as usual.