Mechanics Illusion on double switches

[GuyQuest]

What type of bug are you reporting? Mechanics

What is the bug?
Zoroark's Illusion ability behaves differently on Showdown than in game. If your front two Pokemon are knocked out in one turn and you need to switch two Pokemon in, and one of them is a Zororark with Illusion still intact, Zoroark will always copy the appearance of the Pokemon next to it on Showdown. In game, however, the side matters. If placed on the right, Zoroark will copy its partner, but on the left, it will not. Here is video proof of in game: In all of these tests the Switch Lite is hosting:

Test 1: Zororark is sent out on the left on the host:

Test 2: Zororark is sent out on the right on the host:

Test 3: Zororark is sent out on the left on the client:

Test 4: Zororark is sent out on the right on the client:

Meanwhile, on Showdown, Zoroark always copies:
Zororark is sent out on the left:
https://replay.pokemonshowdown.com/gen9vgc2024regh-2198037275
Zororark is sent out on the right:
https://replay.pokemonshowdown.com/gen9vgc2024regh-2198035846

Are you able to replicate it? If so, how?
Have an untouched Zoroark enter the battle the same at the same time as its partner after a double KO.

 

[DaWoblefet]

The cartridge behavior is not an issue of slots, but of Speed. After multiple KOs, Pokemon are replaced in order of the speed of the Pokemon that fainted. Whenever you were replacing Lilligant with Zoroark, Armarouge was still in the back for it to properly disguise itself via Illusion. But when you were replacing Torkoal, Zoroark is sent out second, and so does not have anything to Illusion as.

Showdown is still bugged in this case though; in the first replay, Zoroark should not have Illusion active. The second replay showcases correct behavior.

Thanks for the detailed cartridge footage for easy reference!