Nintendo has posted an information update for player that are having issues with Walking Wake and Iron Leaves Tera Raid Battles and have not updated to Version 1.2.0 of Pokémon Scarlet and Violet. Pokémon Scarlet and Violet Version 1.2.0 was posted online on February 27th, 2023. Our Pokémon Scarlet and Violet Patches page has been updated with the latest details.

Issue With "Walking Wake" and "Iron Leaves" Tera Raid Battles (Pokémon Scarlet / Pokémon Violet)

Please allow us to explain the support planned for players who caught Eggs from Tera Raid Battles instead of Walking Wake or Iron Leaves due to participating in the battles before updating their Pokémon Scarlet or Pokémon Violet game software to Ver. 1.2.0.

If a player caught an Egg instead of Walking Wake or Iron Leaves in their Tera Raid Battle, their game software will no longer allow them to catch those Pokémon. We have an update planned for release by the end of April that will fix this issue and allow players to catch Walking Wake and Iron Leaves.

We will also bring back a Tera Raid Battle event for Walking Wake and Iron Leaves when this update is released so that players who caught Eggs instead will be able to catch one of each of these Pokémon. More information on the update and the return of this event will be announced closer to the release of the update.

We apologize for the trouble this bug has caused for the players who experienced it.

Source: https://en-americas-support.nintendo.com/app/answers/detail/a_id/61374/