Ovoo only gathers 1199 stone

The ovoo sometimes(?) gathers only 1199 of the 1200 stone on the stone mine. Maybe it has something to do with the changing stone per minute between ages?

Empty stone mine – Screenshot - 923996842719b47a2e9635dbbb9f002c - Gyazo

Only 1199 stone gathered – Screenshot - 0042a6e77d4173e1e6a073eacd14ff8e - Gyazo

Thank you for reporting @ThicksetWind382! The team will check this out.