Let's fix the beginning balance of your reconciliation, rodrigo3,
If this is your first time to reconcile your account, just edit your opening balance (first transaction). Then, mark it as reconciled (mark with R). You can refer to this article: Fix beginning balance issues during your first reconciliation in QuickBooks Online.
If you've already reconciled before, you'll want to check for changes in the past reconciliation period. This will cause an incorrect beginning balance on your next reconciliation. Please refer to this article: Fix beginning balance issues if you've reconciled the account in the past QuickBooks Online.
You can always go back to this thread if you need more help.