Speak to someone at your lender.

Escrow is simply the estimated payments for your insurance and taxes. And it's adjusted annually after the actual insurance and tax bills are paid.

Each year, your lender sends you an explanation of the escrow distributions. That's where you saw the "escrow shortage" mentioned. If you think it's incorrect or if you don't understand it, you need to talk with them.

You are usually given the option to pay the escrow shortage in a one time lump sum, or pay it off gradually via a higher monthly payment. You have likely chosen the latter and are getting confused by that "extra" amount.

It's unlikely that you are paying too much. Talk to your lender and they will explain it to you.