Sio/Nat I noticed something the other day on the reg office, when i auto buy at the start of a round, sometimes i end up with a smoke grenade?

I'm not sure if its supposed to block smokes or not I put it in autobuy cuz the dust2 server allows smoke, but on office like 4 of 9 rounds it gives me smoke grenade when i autobuy

i took it back out of autobuy but ya..sometimes it would block the smoke but sometimes i ended up having one