[GAMEPLAY] Ardent Censer buff not applying if far away

I recently discovered that healing your teammates while over 1500 units away from your teammates (~the range of rank 2 kogmaw ult), the AS+on-hit buff from Ardent Censer won't be applied to your teammate. Now the Windspeaker's Blessing (keystone) buff works at any range, so this seems like a bug.

Reproduction rate 100%, just level soraka to lvl 6, buy Ardent Censer, use your ult to heal someone far away and watch their buffs. Windspeaker's Blessing will apply but Ardent Censer won't.