Hello darenlin,
Welcome to Community! Reconciling your accounts in QuickBooks Online ensures your books are accurate and up-to-date. When you're not able to reconcile your account, there are a number of possibilities, that are affecting the reconciliation process.
Follow this link to review the reconciliation process, to ensure all steps have been taken, in preparing for reconciling your account. If you're still not able to reconcile your account, the best course of action is to contact our Customer Care team outside of Community. With your consent, they can work with you in real-time and ensure you're able to accomplish your QuickBooks goals without delay!
Feel free to reach back out, if you have any other questions. We would be glad to assist!