Note: I’m not sure if it’s a bug or not, but if it’s not a bug then maybe make it so it does work like that? 
If you are low on ammo or use the “need ammo” quickchat (V-2-2), big ammo crates and dropped ammo packs have an ammo icon above them. But, friendly Fire Support mercs and ammo stations don’t have that icon.
Idk if it’s a glitch or not but maybe make it so if you need ammo, you will be able to see the icon above friendly ammo stations and above Fire Support teammates