Thanks for joining the thread, @YTK. Allow me to share some insights with you.

You can consider creating a journal entry to correct these negative balances. In your case, I also suggest checking your bank statement and consulting your accountant to ensure you're accounting for the amounts correctly while using the journal entry. If you need one, you can check this website: Find a ProAdvisor.

Once you're ready, I'd recommend performing this process monthly to monitor your books accurately. For the step-by-step guide, you can reference this article: Reconcile an account in QuickBooks Online.

Furthermore, take a look at this article for more details on how to set up a bank or credit card subaccount in QuickBooks Online connected to your online banking.

Let me know if you have other QuickBooks Online concerns. I'll be checking my notifications to help you soon. Take care and have a prosperous day!