I have reconnected my bank accounts and one has now gone out of balance with QB. This happened previously & made a huge mess of my account. Why does this keep happening?

Thanks for laying out the details of your concern, @DebatEntify.

The syncing of bank transactions in QuickBooks Online (QBO) will depend on your bank. Thus, you'll want to reach out to your financial institution to see if there are any ongoing problems with connecting your account to QBO.

You can also share the name of your financial institution. So I can review any related issues with your bank on my end.

Otherwise, I'd still recommend double-checking that all of your transactions match the ones on your bank statements. You may also find the following articles useful:

• What to do if you can’t find downloaded transactions in QuickBooks Online
• Manually upload transactions into QuickBooks Online

On the other hand, I suggest contacting our Technical Support Team. I understand you've already reached out to them. However, it would be best to contact them again. They have the tools to look into your account and perform a screen-sharing session to do further investigation into this behavior.

Furthermore, I've attached the following references for your convenience to view various guidelines that will assist you in reconciling your online transactions: Learn the reconcile workflow in QuickBooks

We're always here in the Community to help if you have other questions about managing bank transactions in QBO. Keep safe, and have a great day ahead!