First make sure you are running AR-F saying N to include Deposits and that all transactions in GL-O areposted to verify that you are in fact out of balance between the two.  Then run Aging and Balance sheet backdated to prior months to determine when it went out.
 
Then you can look in the GL for transactions posted to the AR account that are not RS (Sales) or CR (Cash Receipt) type.  It is also possible that smebody entered an AR Voucher and designated it as Beginning Balance which would hit Aging but not GL, or they entered an AR Voucher but posted the GL to the AR account rather than a sales or expense account which would also have the effect of hitting the aging but a net 0 amount to the GL.

I am having just the opposite.  Our AP ageing is more than the GL amount; and the GL amount is correct.  The Ageing goes back to the beginning of our database (1999)

Wouldn't you need to post a GL transaction (by GL Journal in GL-B) for the $3625 with a transaction date of 31 December 2021?  Then reverse the transaction on 1st January 2022. I presume your sales revenue is correspondingly understated by $3625.
 
I would be wary of making changes to the GL tables through Maintain Database.