BoE Broken? (in General)

I have a BoE equipped on my SG minion and I recently decided to train some SS to further increase my AC. When I have it trained on that minion it does not get an increase at all, but if I equip a corn it does. If I understand correctly it should get a flat 5% increase. Did I overlook something else?

I also have CML and a MS equipped on this minion, but with my AP my penalties are reduced to 4% so I should still be getting a 1% increase to my SS.

It seems there is some sort of rounding issue because I am not getting the 1% bonus to DD I would be getting from the BoE even after penalties.

AP only halves the *net* bonuses + penalties. If all the bonuses and penalties of your armor added up are negative, AP will halve that final value. If the net bonuses and penalties are positive, AP does nothing.