Guild quest completion status not updating

Several of our guild members have completed their guild quests but the guild list and the quest completed count are not updating. Their guild quest still says "open" in the guild list even though they have completed it. It is no longer in their quest list.

One user was able to refresh and that resolved it, but this doesn't work for others. At least one of them has been waiting for over an hour, so it doesn't appear to be lag.

Help, please!

EDIT: Our guild is Ares Platinum Python (on Ares, of course)

this is a long shot, but try having the guild leader clear cache and refresh browser.