I can't fix it for you now, but here is my tip. Start using subevents, your events are probably conflicting. Think of what is more important first and start sub dividing the other events. For example..
|-PlayerDectect (x) is moving > Add stamina
| |_PlayerDetect is on floor
| | |____- PlayerDetect is Running > Subtract Stamina
| |_ Else
| |___ PlayerDetect is Falling or is Jumping or is WallGliding > Add stamina
Another tip, don't update the width of the stamina bar directly, create a variable for stamina and add and subtract values of that variable, then update the bar's width based on that variable
bar set width to maxBarWidth * (currentStamina/maxStamina)