I have the same problem and I bank with Lloyds. I just called my bank and although this is apparently a change that is rolling out 'across the board' there is very little info out there about it. They were extremely vague and said they couldn't go into too much detail but said that it was to do with PSD2 Open banking and changes in the legislation which meant basically that certain types of accounts (i think personal ones not business ones..) will no longer be able to share their information with third parties like quick books for the foreseeable future. It was like getting blood out of a stone to get an answer out of them but it sounds like only business accounts will be usable from now as far as this rep was concerned. Surprised there isn't more info about this available.
As far as we are aware, there has been no knowledge of personal bank accounts not being used for open banking and being stopped. Both personal and business accounts have and are moving over to the new open banking system. Do you get an error codes or messages with your Lloyds bank account in Quickbooks.