I don't know if it's a bug, but I've seen it happen several times where players lose % of their characteristics during the acquisition process, and you get a roughly equivalent XP boost (I think) in the % to be redistributed.
I don't know if it's a bug or if it's deliberate, and if it's deliberate I don't really see the point.
I think it's happened to me at least 3 times already

Hello, this is obviously deliberate, and was introduced at the request of the community when the new collective training system was introduced.

I'm a bit lazy to read everything :)
But if I understand correctly, when a characteristic has not been trained for a certain period of time, it goes back to zero but the % acquired is not erased and is put back into the common pot of XP acquired.
Is that correct?

Demi-cerveau: Bonjour, c'est évidemment voulu, et ça a été instauré suite à une demande de la communauté, quand le nouveau système d'entraînement collectif a été mis en place.

#forum?topic=165392

Don't rub it in

myforsans: J'ai un peu la flemme de tout lire :)
Mais si je comprends bien quand une caractéristique n'a pas été entrainée pendant un certain temps elle retombe à zéro mais les % acquis ne sont pas gommés et sont remis dans le pot commun des XP acquises.
C'est bien cela ?

That's exactly it

OK thanks for the answers

After 30 days without training in stats, the % are converted back into individual XP

If I'm not mistaken, that's 70% of the state percentage converted into xp

40 days, I think, from personal experience.