I logged in after 4 days away, to find that most of my curio's had finished studying, however my toy chariot had 0% complete. I removed it, then placed it back in to study again, and only then did it start studying.
Later in the evening I logged back out for a few hours while I went to bed (aprox 7 hours) only to log back in and find a dandelion and ant soldiers to have only completed 25%.
I am using amber client, and this only appears to have started happening since the last update. If it helps I always 'log out' of the game, instead of simply pressing the big red X.
Thanks for any help. Dan