Let me provide you with some steps to resolve the banking password in QuickBooks Online (QBO).
Please make sure that you've changed your credentials on your financial institution website first before changing the information in QBO. If you still can't connect, I'd recommend performing troubleshooting steps to isolate the issue.
First, access your QBO account via incognito to check if it's browser-related. These browses won't save any cache or history.
Here are the shortcut keys:
Press Ctrl + Shift + N (Google Chrome)
Ctrl + Shift + P (Firefox)
Control + Option + P (Safari)
Once logged in, go back to the Banking page, then re-change the credentials. Let me guide you how:
Choose your bank, then click the Pencil icon.
Select Edit sign-in info, then type your new password.
Hit Save and close.
If Error 103 appears, select the Reconnect my account link, and enter your new password.
If it works, return to your default browser, then clear its cache and cookies. This process aims to speed up your overall browsing experience and may clear up some room on your computer or mobile device. Using other supported browsers is a good option too.
I've attached an article about what to do if you can't sign in to your account, updating an email address, and managing to a bank.