Script stops running after a few seconds? Even with while true do?

Alright so I'm trying to make a payload, and I just recently learned about Region3. The question I have is that the payload stops moving (after a couple of seconds) even when I'm inside the "Region / PayloadZone", If I leave the PayloadZone and come back, it still doesn't move. It's in a while true do loop so it shouldn't be stopping. There's no error messages, and it displays that it's still searching for parts.

local payload = game.Workspace.Payload
local payloadZone = game.Workspace.PayloadZone
local inZone = game.Workspace.InnerZone
local payloadBVel = payload.BodyVelocity
local inZoneBVel = inZone.BodyVelocity
local pos1, pos2 = (payloadZone.Position - (payloadZone.Size / 2)), (payloadZone.Position + (payloadZone.Size / 2))
local region = Region3.new(pos1, pos2)

while true do
    wait(1)
    payloadBVel.Velocity = Vector3.new(0,0,0)
    inZoneBVel.Velocity = Vector3.new(0,0,0)
    payloadZone.Position = inZone.Position
    print ("Searching for parts to be in the Zone")
    local partsInRegion = workspace:FindPartsInRegion3(region, game.Workspace.Terrain, 50)
    local playersFound = {} --Table of players found in Region
    for i, part in pairs (partsInRegion) do
        if part.Parent:FindFirstChild("Humanoid") ~= nil then
            print (part.Parent.Name, "Found in the Zone!")
            playersFound[part.Parent.Name] = part.Parent --Add Player's Character to Table
        end
    end
    --Effect of being in the Zone
    for plrName, char in pairs (playersFound) do
        payloadBVel.Velocity = Vector3.new(-3,0,0)
        inZoneBVel.Velocity = Vector3.new(-3,0,0)
    end
end