Zed hurt by AOE during ult [GAMEPLAY]

I have noticed that whenever zed ults he still gets hurt by abilities that arent DOT. Ive seen them happen to myself as i play zed and to others. One instance in a featured match i saw him die in the middle of his death mark because he got hit by blitz ult during it. Another time a zed on my team ulted while katarina ulted and he still got damaged by her ult. Ive played multiple games with zed and it happens usually as if he was there instead of untargetable. Im not sure if its aoe only but its happened with tf gold card where i avoided it but i still get stunned.

1.Use an ability on zed 2.Have him ult right before he gets hit 3.He will still get the damage dealt and whatever cc it applies