Welcome to the Community, @colinandgabe-big.
I understand how important it is to connect your bank to QuickBooks Online to sync the transactions easily. Let me share some information to connect your bank accounts.
I recommend contacting your bank if there are any modifications or updates.
It's a positive sign that there isn't a big problem if you can sign in. After that, take a look at the following:
Return to QuickBooks if everything appears to be in order:
Refer to this article for the detailed steps in fixing an error for online banking: What to do if you get a bank error or can't download transactions in QuickBooks Online.
If there's no issue, it is best to reach out to the QuickBooks Online Support team.
You may check out this article if you want to upload your transactions manually: Manually upload transactions into QuickBooks Online.
You're always welcome to drop a comment below if you need more help with banking errors. I'll be sure to get back to you. Take care always.
You have clicked a link to a site outside of the QuickBooks or ProFile Communities. By clicking "Continue", you will leave the community and be taken to that site instead.