Gameplay issue with kayle

Hello Riot i have noticed the kayle's healing ability has weird out comes when used on different champions i think magic resist might have something to do with it because when i read the spell it claimed to heal around 220 but only did 144 to a champion with 100 magic resist and later when i healed another champion with lower magic resist it healed higher then the amount it claimed. this just seams like something to look into thanks for your time bye.