I’ve had this bug 4 times this event, plus once during the last one.
Chest drops stop and are replaced by drops of 10 rubies. Plus, in this event, the doubled egg quest rewards revert to the standard amounts.
Closing/reopening the game won’t fix things. I’ve had to delete/reinstall each time. I’ve lost out on egg tokens through not noticing the bug until after completing quests, plus I’ve lost out on a ton of chests.
I’ve logged a ticket. But seeing as the last 3 I logged were closed without reply, I thought I’d post here too!