All zombies in Unturned always react to noise or if you're too close to them, right? Like when you fire a gun, they are drawn to the sound of that gun being fired. But why is the zombies in A6 Polaris Deadzone (the nuclear plant) suddenly chasing me the moment I step my foot into that area? I play in single player, have max skill in sneaky, all guns have silencer or built-in silencer, yet they immediately chase me the moment I enter the deadzone.

Is this a bug or intentional feature? If it's a bug then I hope the dev of this mod will notice it so it'll be fixed. If it's an intentional feature, is there a way for us to somehow sneak in without alerting the zombie?

Here's an additional preview video of what I meant. Sorry for low resolution and low fps, potato laptop user. https://youtu.be/4hUYiFJ8N_I