Lich's Mastery not preventing damage

Cfwraith

Was using Lich's Mastery to stay under 20 life in the black nodes of power. Had 2 on the field and had the prevent damage icon on my planeswalker when the AI dropped a creature, did not deal with the support and dealt lethal damage.

Mburn7

There are a couple cards now that can remove prevent damage.  Did either of you have one of those effects in play?

This card has been extremely buggy since it came out, but it's supposedly been fixed now.

Cfwraith

no i think having 2 Masteries **** out the prevention. just replicated it.

Unknown

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