Giant Cindermaw

• WWizards of the Coast2022-10-14
  Official Ruling
  Spells and abilities that cause players to gain life still resolve while Giant Cindermaw is on the battlefield. No player will gain life, but any other effects of that spell or ability will happen.
• WWizards of the Coast2022-10-14
  Official Ruling
  If an effect says to set a player's life total to a number that's higher than the player's current life total while Giant Cindermaw is on the battlefield, the player's life total doesn't change.

Rulings via Scryfall