Hi there, ragerservices.
Banking error 377 occurs when QuickBooks Online (QBO) is unable to download the transactions due to connection type updates from your bank. To resolve this, you can manually update your bank account.
For more details about resolving banking error 377, you can check out this article: Resolve Error 377.
I also found a helpful article for more details about fixing banking errors: Fix online banking errors in QBO.
Please reply to this post if you need anything else. I'd be glad to help.