Everytime I use the the secure payment gateway for sainsbury’s online groceries it errors multiple times after I’ve approved from my monzo card. The gateway states this page is owned by the bank. In my latest try it took 10 attempts and still didnt go through…
Get the Auth code sent by text instead as a work around. I have a similar intermittently issue with their Argos website. Although that’s worked this month for me whereas last month it didn’t.
Edit - meant to add Sainsbury’s groceries works fine for me.
Yeah I have the same issue with Sainsbury’s check out. As @DaveJ says request the auth by SMS and it works.