Greetings everyone.

I just joined this game like a month or so ago and slowly started leveling as a healer. Now there is 1 thing that is kinda weirding me out and its getting increasingly annoying.

Sometimes my spell is getting interupted without me being actually hit. The fights i noticed this the most are fights with big aoe attacks (primals Ifirit and Titan are prime examples here) Like i get out of the aoe circle and start casting a spell but when the aoe fires off my spell is getting interupted.
Is this some sort of effect from big aoe attacks or am i doing something that causes this? I am not using any macro's so that can't be it. I nearly losted a couple groupmates because of this so now i am trying to find the cause.