I have been having this connection issue for the past two weeks. I reset the account and set it up again a few times, and it solved the problem temporarily, but it returned again. Here is the error:
Citibank is reporting connection issues
Connections are blocked from $scheduleStartDate $scheduleStartTime PDT to $scheduleEndDate $scheduleEndTime PDT.
You'll be able to reconnect after this time.
This is only one of a couple of issues that I am consistently having with connections to my different bank accounts. Honestly quicken was much more stable before they turned it to this subscription model a few years ago. They are charging more but they simply are failing to deliver the basics which is stable connections to financial institutions to download transactions. And because this is happening with different banks, I can't blame banks, I think it's quicken that can't catch up with changes in the Fintech world.
On the latest update, I also noticed a weird issue, that certain transactions were added to a different account from the same bank.