Some misguided manager decided to retain relationship to child by first marriage of second spouse of your 5th cousin in the mix for calculating relationships. Some argued quite strenuously for having only blood relationships in there, but they would not listen.
You can not change this. There are no options in the Ancestry.com calculator.
Other tree sites, such as using The Next Generation (TNG) software have a much more sensible relationship-calculator setup that also shows all kin throughput very clearly. It can be done.