Can someone please help me with this problem I have with Excel autofilter.

I applied an autofilter to a list of data that does not exceed the 1000
items limit, and attempted to filter the data to get a particular item. The
filter did bring up all the items needed, but it also had at the bottom of
the filtered list, another item that was not part of the items to be
filtered, which unfortunately affected my subtotal calculation. Can some one
please advise.

Thanks so much