OKay, the old problem is that it didn't work on a WaW map. The new problem is that it doesn't work on Anctoville, an official map.
The British Rifleman on Anctoville has a throw-able Mills Bomb. He also has the Cup Launcher on his No.4 that can launch Mills Bombs, using the same ammo count as the thrown ones. Anctoville is a small map, so the limited grenades code (where you only get one of each type of grenade you are equipped with) is active. So you get 1 throw-able Mills Bomb, one No.4 Heat Grenade and... 3 Launch-able Mills Bombs. If you throw your one Mills Bomb, you can still Launch 2 more out of the Cup thing, so the the weapons are obviously ammo-linked. This obviously isn't correct, because, for example, on Pointe Du Hoc (another map with limited grenades code), the American Rifleman has one throw-able Mk.II Frag Grenade, one Garand Heat Rifle Grenade and one Launch-able Mk.II Frag Grenade; in that kit, the two Frag Grenades are ammo-linked, meaning if you throw one, you can't launch one unless you get more ammo.
I believe the problem is that the No.4 Mills Bomb Launcher was omitted from the Limited Grenades code, similar to how the German HEAT Rifle Grenade was omitted from it for 2.2. It's just that this incarnation of the same oversight has a funky side effect because the No.4 Mills Bomb Launcher (not limited) is ammo-linked with the thrown Mills Bomb (which is limited). The net effect is that the British on Anctoville have more grenades than the Germans, with the added oddity of only being able to launch the extras instead of throwing them.