Transaction appears in two different accounts

I have an Express Cash Account card (debit) with my credit union that I use in lieu of carrying cash with me. I use it for small purchases such as a soft drink etc. It typically has a small amount such as $20 and when it lowers to $5 or so, I transfer money from my checking account to the Express Cash Account card. 

I recently made a credit card purchase in the amount of $20.59 and entered it as a transaction into my Citi Bank credit card account in Quicken which included several other credit transactions. I have received a credit card statement and paid the entire credit card amount in full which was about $325.

In my Express Cash Account register in Quicken the same amount of $20.59 is showing which throws off the actual balance in that account. When I try to delete it I receive the following: "This transaction is a transfer to a split and cannot be deleted here." 

I have no idea what that means since that amount in my credit card account is not a split entry transaction and I have no idea how the $20.59 got into my Express Cash Account in Quicken which has a $28.00 balance but is showing differently in Quicken. I would like to delete it so the correct amount on the card agrees with the credit union amount.
See attached Jpeg.