Hello, I've had this issue as well, all the transactions from one month are on the

bank transaction tab, all financial reports, and on the registry (on the chart of account). I finally solved this issue!

First, go on the transactions tab, then on the chart of accounts, find the bank account and under action you will click 

View register. On there make sure that all transactions that are not showing on the reconcile tab, have the letter "C" under the check mark. There are 3 options to choose: C, R, or blank.

I noticed that even thought I did not reconcile January all the transactions from that months showed as reconciled

(R) | had to manually change those 

transactions to cleared (C) for the to show up on the reconcile tab.

I hope this helps and if you have any questions please let me know