Not sure if this helps but I have had the same ongoing issues with connections to First Direct.  It came to a head the other day when using the new inconvenient method of entering security details everytime I did a bank update, this failed and started to ask me to reset my sign in details asking for login name, password and memorable information ..... I was unable to get past this and seemed to be in a never ending loop.  I spoke with First Direct and they checked all my details and said it wasnt on their side and that I should only ever be asked for 2 security questions.  I then contacted my Accountants who provide my Quickbooks subscription and asked if they could remove my bank account and then re-add it.  This was done and I was asked the usual two questions and had to generate a logon code from my phone app.  Once this was done everthing worked fine and even better it no longer asks me to enter these details each time I do an Update.  At least that has been my experience to date.  Hope this helps.