Help! How to make Bugfree health

I want to create an action that changes Mei’s health from 250 to 200, but I’m running into a problem.
For example, if you want to change the health from 250 to 200, use the “Set Max Health” action.

rule ("Rule1") {
    event {
        Ongoing - Each Player;
    actions {
        Set Max Health(Event Player, 80);

Performing the action like this will successfully bring Mei’s health change from 250 to 200.
In this state, use Junker Queen’s “Commanding Shout”. Then, the extra health added will be 40! (Usually 50. In other words, “50x0.8=40”.)
This is a problem because I want the code I create to be as close to the normal game mode as possible.

If anyone knows a solution, please let me know right away.

try just editing the health in the normal custom game settings