There should not have been any differences between Dec and Jan. Bank Reconciliation *should* be month to month and have nothing to do with Year End. Is there any common theme to the discrepancies between Dec and January.
Some of the common issue are:
- Something that had be Reconciled was modified and it is now UN-Reconciled
- Someone got mixed up between 2021 and 2022 and entered something in 01/21 by mistake
- Someone moved something into Dec to make it look like a 2021 transaction
- Bank Feed items was not correctly matched to an entries but "Added" as a duplicate
First check would be to take the Dec Statement and start the Reconcile process. Put in the Dec Closing Date and the Closing Bank Balance. Check to see what, if anything, is NOT Reconciled and also confirm you have a $0 Balance and if so, Dec/2021 is still correct.
If things don't match up, start with those items and see if you can figure out what happened.
Luckily you are using the Desktop version, so you have the option to Undo the months you've already Reconciled. So go undo back through Dec (even Nov if you want) and then move forward again to get things back in line.