The client received $1,065.97 for the 1st Economic Impact Payment and $515.97 for the Additional Economic Impact payment. 

Double check the actual amounts received.  Could it be that the amounts provided to you were off?   That combination seemed to be at odds per my preliminary computation. 

There is a way to check the IRS' records of EIP amounts.  You may want to verify the accuracy of those amounts if you want to get to the bottom of it.