Assuming you're using filtering enabled, they're staying the same because they're only changing locally. To change the values "officially", you have to do it from a serverscript.
- Either subscribe to the "PlayerAdded" event in a serverscript, and then subscribe to that player's "CharacterAdded" event, changing the values of the humanoid from there,
OR
Make a script in "StarterCharacterScripts" (Serverside of course), and then edit the humanoid values. Though, in order to get the humanoid, you have to do this line of code first:
local humanoid = script.Parent:WaitForChild("Humanoid")
This is because everytime a player's character is loaded, this script will be parented to that player's character. :WaitForChild("Humanoid") is optional, but recommended, since the humanoid could have a chance of loading late, thus making the script think of it as "nil", causing an error.