Detect INVIS unit AURA?

Hi ! I am trying to make an aura spell based off the true sight spell for human towers (ya know, with the blue eye)...and it does NOT seem to let me change the area of efect. Its a hero spell, and right now i want it to be 300 at lvl 1, 500 at lvl 2 etc...but it is always staying at 300, so units have to be very close 2 be revealed even at lvl 3!!

Does anyone know why this is, or whether this is just a screwed up ability issue that may be resolved with the final 1.15 patch from blizzard?

*bump* da dump* da *bump*

first of all, i think there's two of those abilities, so it might be that you're editing one, and giving the other to the unit.... but this is just me, so i could be wrong...
second, why not make an AURA with it ? just look for a "custom auras" tutorial, and give "true sight" to every unit nearby (a true sight aura), hence improving your inviso detection.....
what i'm saying is "instead of making your true sight detect more ground, make it so it affects more units".
and what's with the spam ?

Have you tried to base it off different spells? There are more spells like that. Examples: the auras from the owl scout, hawk and shade and there is an item that gives such an aura.