So, it seems that Southsun Survival has a new bug where the Immobilized condition is briefly removed when the match countdown finishes, but before the match officially begins. This allows players to dash to the campfire and start grabbing items, and most usually take advantage of the situation by grabbing arrows/pistol and killing as many players as they can when the Immobilized condition is applied again.
I think it’s a funny bug personally, and it does make it easier to farm kills for the achievement, but I’m guessing this is something QA should look at.
Oh, and there’s also a hilarious secondary bug where Rangers that join the map, but have not fully zoned in yet, have their pets not being Immobilized either. If an active player hits the pet with an attack, the pet retaliates and usually OHK’s the offending player due to their miserable 1000 health.