Pokemon Sleep is currently experiencing a range of in game issues affecting the home screen, certain Pokémon and specific main skills. Players have reported problems tied to Darkrai, the move Bad Dreams (Charge Strength M), Heracross and Bulk Up (Cooking Assist S), along with other related features. The issues appear to impact skill activation and general usability, which may disrupt normal sleep research sessions. Developers are aware of the situation and are expected to roll out fixes, so players may want to keep an eye out for an upcoming patch.
Source: Official Pokémon Sleep news and PokemonSleep.net