[2019] Infected Private Match - Can’t Use Throwing Knives

Had a group of 15 last night in a private match trying to play infected. We could not get it so the infected would have throwing knives...anyone else having this problem?

Go into advanced settings, set the infected lethal to “throwing knives,” but CAN NOT SAVE IT. Every time you exit the advanced settings and go back in it has reverted to drag grenades.

I tried saving it as a custom game but same thing...

Anyone have a solution for this??