Scoreboard health/ atributted skull bug

I have a wither skull with attribute +80 Max Health

then i have scoreboard criteriaTyped health.

so i equipped the skull and i healed myself so i get 100 health.

then i removed the skull then the scoreboard still says i have 100 health (i dont know if its bug)

then i did /effect JMZuniga 7 1 0

it killed me, but no damage.then my scoreboard health went back to 20.

then my player model apperead like dying (glitching actually)

then i reported it now