Hello and welcome to the Community, balticustabby-gm
We're not aware of any issues impacting the bank connectivity between Revolut and QuickBooks Online.
Since it's been a while since you last authorised the connection, it's likely that the Open Banking authorisation period has expired and requires re-authourising.
First, log into your banks website and look for missed prompts that need your confirmation. Acknowledge the prompt, then go back and refresh your account in QuickBooks Online.
If you don't see a prompt to re-authorise on your banking dashboard, please disconnect and reconnect the account in QuickBooks. Before you disconnect, review your bank transactions in QuickBooks and check the date of the last transaction to prevent duplicates from being downloaded when you reconnect.
To disconnect, click the pencil icon (above the bank balance in QuickBooks) > select Account info > Tick Disconnect this account on save > Save. You can then follow the steps in our guide to connect your bank account.
If you run into any errors when connecting the account, check out our guide on how to fix banking errors.