Yeah, they've been messing around with equipped items on top. Here's what one of the devs said about it.
Source
I actually fully agree with him. The QD inventory mod puts equipped items on top, and I loved it at first, but it is extremely annoying when dealing with long lists and changing what is equipped. I think the best scenario would be equipped items are on top by default, but when you sort the list by something (weight, damage, v/w ratio) equipped items should be sorted just like everything else.