Thank you for posting here in the Community @Gee4.
You don't have to worry about the outdated bank balance since it does not affect your books.
A connectivity issue may prevent you from downloading transactions into QuickBooks.
If you want to learn more about manually uploading transaction in QuickBooks, you can refer to this article: Manually upload transactions into QuickBooks Online
Please comment below if you have confusion. I'd be glad to help you. Have a nice day!
