Reply to Modifier Combo button mapping

Need Help!!!

I'm trying to map a modifier by the combination of 2 buttons.

So...

B1 = Mod 1 Value 1
B2 = Mod 1 Value 2
B1+B2 = Mod 1 Value 3.

It kind of works (with 2 duplicate condition inputs of both Mod values)

But... It doesn't release back to 0 state. It sticks.

Need some kind of release, or reset, without hitting a button.