Smooth Doom Bugged BFG9000

I was playing deathmatch with bots and notice my BFG9000 ammo was not going down

I only have smooth doom enabled and the only cheat I used in this video was to give myself the BFG9000.

Please tell me what is happening; if it is the mod or something else.

This does not happen on vanilla doom.

Footage:

Happening with all weapons or only BFG? Does it happen in single player? It looks like it's getting the ammo restored at the end of the fire state / return to ready state, because I briefly see it drop to 560.

Only the BFG9000, also it does the same in doom2 as well.

It happens in single-player and multiplayer

lol For some reason the BFG gives the player 256 ammo when fired.

That means always use bfg and never mind