I think you overengineered it a bit…
Can you try this setup of 3 functions and tell me if it works for you:
Where
Stamina Change is how your stamina is regenerating or draining (depending on the sign) per second.
The benefits are: No timers, no delays, Stamina is calculated only when needed.
The caveats are: You have to go through GetStamina() to have it properly calculated before using it.
Edit: I wasn’t sure for the ContiniousStaminaChange weather you want your Change per Second to modify the Stamina Change or override it. It is currently overriding it but you can modify instead.