When the player has a filter on the ammo slot that doesn't match the content of the ammo loader, the ammo loader still feeds him, and since it can't put them, actually void the ammo (example: I had a uranium ammo filter on my submachine gun to keep the slot empty and allow me to jump in space. The chest with piercing round keep tried to feed me, resulting in actually voiding the ammo. Took me a while to figure out the problem). Blacklisting the player, or removing the filtered slot solved the problem in both case, confirming the problem is with the filtered slot on the player entity

edit: title should be has, sorry!! English is not my main language but I'm still ashame by that mistake