I am having a problem with my sprint bar. When stop for the sprint bar to increase but start running again while it increases it also try's to decrease at the same time

The name needs to be exactly the same. Maybe just change it to ‘Stamina’ for now.

( change both your event and the name in the begin play event )

You can also check it’s running with a print string.

You also have to set MinStamina and MaxStamina to sensible things.