How can I update .Magnitude more effectively?

The titles a little vague, my apologies I didn't know how to word it. Basically, I'm creating a boss, and while the player is within 50 studs of the boss it will move towards the player constantly, this works fine as well as the attacks (I don't want to use pathfinding, so I'm using :MoveTo()). The issue is that when the boss respawns if the player is already within 50 studs the boss will sit there dormant. Here is the code I'm using to do this:

local Found = false
local B1 = false
local attacking = false

while wait(1) do

    local DBMpos = workspace:FindFirstChild("CaptainTennileImposter").HumanoidRootPart.Position
    local PlayerPos = game.Players.LocalPlayer.Character.HumanoidRootPart.Position
    local magnitude = (DBMpos - PlayerPos).Magnitude

    --Make sure he's alive
    if workspace:FindFirstChild("CaptainTennileImposter").Humanoid.Health > 0 then

        --If the players close then he'll move
        if magnitude <= 50 then
            if B1 then

                if (DBMpos - PlayerPos).Magnitude <= 5 then
                    game.ReplicatedStorage.BossReps.DBMAttack:FireServer()
                end

            elseif not B1 then

                B1 = true
                game.ReplicatedStorage.BossReps.InDarkBlueMoon:FireServer(game.Players.LocalPlayer)

            end
        else
            B1 = false
        end

    end
end

I originally had it at wait() but it ran better to wait(1). What can I do to make it so that If the boss respawns and the player is within the 50 studs it will move? I have a print statement setup in the server side to detect when the player first triggers movement, but this doesn't fire when the player starts within 50 studs of the boss.