thttps://www.youtube.com/watch?v=SZdVrG-dH_0&ab_channel=DoltHHaven

This isn’t a bug. A Toretoise will happily snack on berries while on cooldown, but won’t get any benefit from that. You can tell by the different subtitles and pitches.

that's not really very intuitive in my opinion. It would be cool if they didn't allow you to feed toretoises berries when they're at full health and on cooldown.