Humanoid.HealthChanged acting strangely. Can someone help?

GENERAL PRACTICE

Make sure the damage being taken is done on the server or else this will only run once.

Use a repeat loop instead of the second while loop (inverse the values), since once the repeat loop hits its criteria, it is bypassed.

Use parentheses when using the :WaitForChild() function

ISSUES

Move the Humanoid.HealthChanged Event outside of the while loop since it has a certain time frame in which to run if placed inside the loop.

I added an extra variable "change" to take the place of the HealthChanged Event in the if-then statement.

The if-then inside the health changed makes sure to reset the value of "change"

Revised Server Script

local waitt = 1
local regen = 1
local timer = 1.5
local canregen = false
local change = false

local Character = script.Parent
local Humanoid = Character:WaitForChild("Humanoid")

Humanoid.HealthChanged:Connect(function(health)
	print "cant regen until not taking damage"
	timer = 1.5 
	canregen = false
	if Humanoid.Health ~= Humanoid.MaxHealth then
		change = true
	else
		change = false
	end
end)


while true do
    if change == false then 
		if timer < 0 then 
			canregen = true 
			print "able to regen"
		else 
			timer = timer - 0.1 
			canregen = false
			print ("cant regen, timer is at "..timer)
			wait(0.1) 
		end
	end

	repeat
		if Humanoid.MoveDirection == Vector3.new(0, 0, 0) then
			waitt = 0.5
		else
			waitt = 1
		end
		Humanoid.Health = Humanoid.Health + regen
		wait(waitt)
	until Humanoid.Health >= Humanoid.MaxHealth and canregen == false
end