Read on below to learn more about Pokémon Sleep:

Update Contents (version 1.4.0)

Thank you for playing Pokémon Sleep!

This update includes the following improvements.
You will need to update to the latest version through your app store.

Update Contents

New Features

■ Preparation for the Raikou Research event
• Please see the event news for more details.

Game Contents

■ Changing the total number of Berries and ingredients that any helper Pokémon can hold beyond its carry limit to 999

Other

■ Making it impossible to discard Master Biscuits

■ Adjustments to show Pokémon sleep styles in order of rarity on the sleep research results screen after snack time

Source: Official Pokémon Sleep news