Not sure if bug or me not understanding the skill behavior but will try to explain it.
Holy Aura:
You and nearby allies passively have 30% Increased Damage and 30% Elemental Resistance. Activating Holy Aura doubles the stat bonuses for 4 seconds.
So Holy Aura works perfectly - both active and passive, but when you spec into Faith’s reward the bug/strange behavior comes.
Faith’s Reward:
Holy Aura grants you and your allies a burst of ward when activated, but Holy Aura has longer cooldown.
Ward Granted On Activation: 400
Cooldown: +5
The expected behavior is that the active effect of Holy Aura (when you activate it) will grant 400 ward but its cooldown will be 15s instead of 10s, meaning you can use it once every 15s to get the 60% dmg, 60% ele res and 400 ward. While on cd the passive effect stays.
What happens is that you get the 400 ward, but the cooldown stays the same - 10s and after the initial 5 seconds you lose the passive effect till the 10s are gone - then it reactivates it.