Could not play any planeswalkers with Fist of the Five Suns and Jodah Archmage on the field.

When playing a planeswalker I was asked to pay WUBRG instead of the normal cost. this error occurred for multiple planeswalkers. the following is the stack trace for the event and was the same for each attempt to cast.

The game exception occurred:

java.util.ConcurrentModificationException
Server version: 1.4.52-V5-beta4 (build: 2023-08-25 15:34)
Stack trace:
java.util.ArrayList$Itr.checkForComodification(ArrayList.java:909)
java.util.ArrayList$Itr.next(ArrayList.java:859)
mage.abilities.AbilityImpl.activateAlternateOrAdditionalCosts(AbilityImpl.java:482)
mage.abilities.AbilityImpl.activate(AbilityImpl.java:284)
mage.abilities.ActivatedAbilityImpl.activate(ActivatedAbilityImpl.java:266)
mage.game.stack.Spell.activate(Spell.java:148)
mage.players.PlayerImpl.cast(PlayerImpl.java:1213)
mage.players.PlayerImpl.activateAbility(PlayerImpl.java:1469)
mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2164)
mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2187)
mage.player.human.HumanPlayer.priority(HumanPlayer.java:1252)
mage.game.GameImpl.playPriority(GameImpl.java:1602)
mage.game.turn.Step.priority(Step.java:66)
mage.game.turn.Phase.playStep(Phase.java:204)
mage.game.turn.Phase.play(Phase.java:90)
mage.game.turn.Turn.play(Turn.java:137)
mage.game.GameImpl.playTurn(GameImpl.java:1095)
mage.game.GameImpl.play(GameImpl.java:1002)
mage.game.GameImpl.start(GameImpl.java:978)
mage.server.game.GameWorker.call(GameWorker.java:34)
java.util.concurrent.FutureTask.run(FutureTask.java:266)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
java.lang.Thread.run(Thread.java:748)

Start at mage/abilities/AbilityImpl.java:482 and trace the alternate-cost activation path from the stack trace. Reproduce the interaction with Fist of the Five Suns, Jodah Archmage, and a planeswalker, then verify that planeswalkers can be cast with the expected cost without a ConcurrentModificationException.

Written by the indexing model from the issue text.