Let's make sure that your bank account has been successfully connected to QuickBooks Online. Being unable to sync the account in QBO can be the reason why you're not seeing one of them.
Please know that QuickBooks only supports the following account types for Online Banking:
Business Account
Personal Current Account
Commercial Credit Card
Savings Account
If can't find the correct bank account upon the connecting it, take note of these reasons:
Your bank has multiple names on our list. Make sure you have selected the correct listing or have tried all possible links. Search by the banking sign in URL to ensure you are using the correct listing.
Your bank does not connect to all types of accounts.
Your bank is not a participating financial institution.If you still can't find your bank, use the Request support for your bank option and ask us to add your bank.
I'm adding here some resources that you can visit about managing Online Banking in QuickBooks: