Voobly has unconventional way of changing binds?

So I'm pretty new still, to AoE2. I installed voobly but hate the AoC defaults, as I'm already used to the hd ones.

Problem is, voobly won't let me change certain keys, because it will automatically unassign the other.

Example: I can't make build a house to Q as well as barracks to Q. It will unassign the first one.

This DOES NOT happen in the hd game under the SAME EXACT BINDINGS MENU.

Remind me again, why do people use this piece of garbage software?