Humanoid.MaxHealth not replicating: Resets to 100 when taking damage (Stat System)

[flat panther]

Hi everyone,

I’m building a Stat System where players earn points upon leveling up to increase their attributes. One of these attributes is Health, which is supposed to increase MaxHealth by 5 points per stat level.

The Issue:
When I upgrade my health, the UI correctly shows the MaxHealth increasing (e.g., from 100 to 200). However, as soon as an NPC hits me for 10 damage, my health immediately drops to 90/100 instead of 190/200. It seems like the server doesn't "know" about the MaxHealth change, so it forces my health back to the default 100 limit.

I am using a custom HUD and a Stat System. I’ve tried changing the MaxHealth, but it keeps resetting or not replicating to the server correctly. When I’m at 200 MaxHealth on my screen and get hit, the health bar suddenly snaps to half-full because the server thinks my max is still 100.

What I need help with:
How can I properly update a player's MaxHealth from a Stat System so the server recognizes the change and doesn't reset it to 100 when damage is taken?

Thanks for the help!

[noble dome]

the ui only changes the health value locally

the server still owns the real humanoid max health

store the players health somewhere and you have to apply it from the server

also if you dont provide code we cant help you out as much as we could

[flat panther]

Here is the part of the code that handles the stat upgrade in my HUD LocalScript. Im updating the MaxHealth here

-- This is the upgrade button inside my HUD LocalScript
statBtn.MouseButton1Click:Connect(function()
local currentHealthStat = player:GetAttribute("Health") or 0
player:SetAttribute("Health", currentHealthStat + 1)

local char = player.Character
local hum = char:FindFirstChild("Humanoid")
if hum then
    -- This is the local change that resets:
    hum.MaxHealth = 100 + (player:GetAttribute("Health") * 5)
end

end)

[fast light]

setting stats like this on the client is meaningless, you create a desync from the server

doesn't matter what the client thinks their health is