"Reconcile" means to reconcile the book balance to the monthly bank statement balance, an exercise that is done once per month. Obviously if transactions are missing then the book balance is wrong, so you can't reconcile it to the monthly bank statement. When you say "after reconcile", you must mean posting from Banking>For Review; that is called posting, not reconciling.
If transactions are missing then you can download a CSV file from your bank's website for the missing date range, and upload it into Banking>For Review
https://quickbooks.intuit.com/community/Banking-and-bank-feeds/How-to-upload-more-than-90-days-of-ba...
