When I tried to use a time booster (14h) during the upgrade of an ancient wonder (ie. Watchtower), the upgrading time did not deacrease, but the booster disappeared from my list...
when i tried this, i could reduce the reamining time perfectly with a time boost without having to refresh.
Has anyone else encountered this in that past?
Issues like this, you should contact support for btw, they can fix it for you then if something goes wrong (and they also pick it up as a bug if this happens to more then 1 person)