Can't Melee Block with Mouse3

[OldGodKing]

So my mouse 3 button doesn't seem to work when click down on it as I'm using a melee weapon. It only seems to occur when it's melee.
With my guns, I'm able to use the mouse 3 for secondary fire but melee doesn't work. I've tried re-configuring my key bindings but I don't seem to be able to fix it.

I've also tried using different mouses but the problem still persists. Has anyone had such a problem before and is there a way to fix this? Because without one of those bindings, I can't go pure melee because I can only either go for channeling or blocking with my right-click. Again, I wanna keep those keys to the mouse and not on my keyboard if possible.  

[NinjaZeku]

Alt Fire simply doesn't seem to want to share. Please look into this, DE.

Just because:

 

[OldGodKing]

I read your thread and yeah, it's the same situation as mine. I've had secondary fire tied to the same mouse3 key as my melee blocking. It has always worked until a few months ago when I found out that I couldn't block and glide while doing spy missions. This needs to be fixed.