"Imbalance-USD"

[JUNIPER]

    My full Visa credit card balance is automatically taken by Chase 
bank from my checking account every month, so far with no problem. The 
latest amount ($2723.99) was taken and recorded as usual, but another 
entry in the exact same amount appeared just above it, on the same day, 
in the "Transfer" column, entitled "Imbalance-USD".
    Any idea why that transaction might have suddenly appeared (plenty 
of money in account)? I presume I can just delete it but it is peculiar 
because it never happened before and no changes have been made by me.
    Thanks!
    Steve J.