End anchorage calculation using Hilti PROFIS

I am using Hilti PROFIS to design the end anchorage of the concrete columns with the existing concrete columns at the slab level. The end reactions include axial compression load, shear forces in both directions and biaxial moments.
I am observing different anchorage lengths: 250 mm when not selecting 'Include reinforcement in compression,' but when this option is selected, the anchorage length increases to 800 mm. Could you please clarify whether this option must be used, as it is expected that the concrete sections will carry all compression forces?