I encountered a gameplay bug with Eaten Alive.

Card text:

“As an additional cost to cast this spell, sacrifice a creature or pay {3}{B}.
Exile target creature or planeswalker.”

During a PvP match, I cast Eaten Alive and the game presented me with the two additional-cost options. I selected the sacrifice a creature option.

The game then asked me to choose one of my creatures to sacrifice. I selected it, and the creature was sacrificed successfully.

However, after that, Arena presented me with Auto-Pay and asked me to pay {3}{B} as well, even though I had already chosen and paid the alternative additional cost by sacrificing a creature.

I paid the mana because the game gave me very little time to understand what was happening.

After that, Arena asked me to select another creature. Instead of allowing me to select the opponent's creature as the target of Eaten Alive, it showed my own battlefield creatures again. I selected one, and that creature was also sacrificed.

Eaten Alive then went to my graveyard, and the opponent's creature was not exiled.

Expected result:

After choosing “sacrifice a creature” as the additional cost, I should only have to sacrifice one of my creatures. I should not also have to pay {3}{B}.

After the additional cost has been paid, Eaten Alive should resolve by allowing me to target an opponent's creature or planeswalker and exile it.

Actual result:

Sacrificed one of my creatures as the chosen additional cost.
Arena incorrectly requested another {3}{B} payment.
Arena then presented my own creatures as the creatures to select.
A second one of my creatures was sacrificed.
Eaten Alive went to the graveyard without exiling the opponent's creature.

This appears to be an incorrect handling of Eaten Alive's additional cost and/or target selection.

Platform: MTG Arena PvP
OS: Android
Game mode: PvP
Relevant card: Eaten Alive