Hi,
i tested the state you are showing and that seems to work on my end,
although i would not recommend doing it this way.
i would split it into 2 states and from int compare point Less Than' to the int add state and also add a wait action (set to 0.1 or so)
because if you do this by every frame, it will differ from each machine it is played on.
For example on a old computer it might be 24 frames per second and on a new computer it might be 120 frames per second.
If you can't get it to work, can you show the check health state.