Hello @CScotty,
You're on the right track with how the opening balance is determined. Since it's still incorrect even after reviewing the accuracy of your last reconciliation, I'd recommend contacting your accountant.
They have the tools needed to help resolve your reconciliation and understand why the balance is incorrect. If you haven't yet, here's a link you can use to find a bookkeeper near you: Business is better with a ProAdvisor.
Additionally, I've also included this reference for a compilation of articles you can use while working with us: Reconcile your bank account with QuickBooks Desktop.
If there's anything else that I can help you with, please let me know in the comments below. I'll be here to lend a hand.
