There is an issue with "Unholy Annex / Ritual Chamber" that has bugged me for some time now.

If both rooms are open, but the player doesn't have a Demon or a Changeling with all creature types on the battlefield, then I still lose 2 life, and they gain 2 life. Why is that?

This is what the text says on both sides:

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Unholy Annex {2}{B} Enchantment — Room

At the beginning of your end step, draw a card. If you control a Demon, each opponent loses 2 life, and you gain 2 life. Otherwise, you lose 2 life.

Ritual Chamber {3}{B}{B} Enchantment — Room When you unlock this door, create a 6/6 black Demon creature token with flying.

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The card specifically says IF you CONTROL a DEMON. This has been an issue for some time on "MTG: Arena". I think that the players who play Unholy Annex know the bug exists and put the card in their decks.

There should be a check in the code. Does the player have a demon?

A) No -> I lose 2 life.
B) Yes -> Each opponent loses 2 life, and I gain 2 life.