More help with collision groups

Help and Feedback Scripting Support
#1

Hello,
I wrote a collision group script:

local physics = game:GetService('PhysicsService')
local collisionGroup = physics:CreateCollisionGroup('group')
local npsGroup = physics:CreateCollisionGroup('npcs')
physics:CollisionGroupSetCollidable('npcs','group',false)


local function main()
	for _, mainPart in pairs(workspace.Teacher:GetChildren()) do
		if mainPart:IsA('BasePart') then
			physics:SetPartCollisionGroup(mainPart,'npcs')
		end
	end
	
	for _, mainPart in pairs(workspace.Guide:GetChildren()) do
		if mainPart:IsA('BasePart') then
			physics:SetPartCollisionGroup(mainPart,'npcs')
		end
	end
	
	for _, doorPart in pairs(workspace.StaffDoor:GetChildren()) do
		if doorPart:IsA('BasePart') then
			physics:SetPartCollisionGroup(doorPart,'group')
		end
	end
end

main()

It works, but when I enable it, it breaks my no-collide players script; players and npos can collide. But they shouldn’t be able to.

Here is my no-collide player script:

script.Parent = game:GetService("ServerScriptService")
local PhysService = game:GetService("PhysicsService")
local PlayerGroup = PhysService:CreateCollisionGroup("p")
PhysService:CollisionGroupSetCollidable("p","p",false)

function NoCollide(model)
	for k,v in pairs(model:GetChildren()) do
		if v:IsA"BasePart" then
			PhysService:SetPartCollisionGroup(v,"p")
		end
	end
end

game.Players.PlayerAdded:connect(function(player)
	player.CharacterAdded:connect(function(char)
		char:WaitForChild("HumanoidRootPart")
		char:WaitForChild("Head")
		char:WaitForChild("Humanoid")
		wait(0.1)
		NoCollide(char)
	end)
	
	if player.Character then
		NoCollide(player.Character)
	end
end)

When I disable the first script, the second one works! How can I make it so that they both work?

#2

I am not getting any errors.