Holy Paladin 4 Piece Bonus Tier 21 Not Working?

[Nystromia]

I have been monitoring the T21 4 piece bonus when using holy shock with a 30% chance to increase your FoL /HL /LoD healing. I don't see the buff to track when it is active. Can someone please help me with the name of the buff?

Thank you.

[Leetchee]

https://pastebin.com/GJT5KcJ2
The buff is called "Purity of Light".
Credit goes to Holyshockzz from the Hpal discord.