Every time the troll camp doesn't drop I put it in storage for a couple of minutes and then take it out again. Seems to help....a little.
The randomness is frustrating. I have just finished my tree in my 50 (lower XP) second kingdom, but still need 3 yellow glitter in my first kingdom. With 3 days left I stay hopeful...
Drops I got from present stacks (that I know of): 2 x nutcracker, 1 x red sleigh (had 1 in inventory), 1x pile of gifts, 2 x winter garden, 1 x winter picnic, 1 x wreath lamp post, 3 x christmas path, 1 x snow gate?, 2 x elf skunkupea, 1 x elf baby golem. Not bad, I guess, even if most of it is just deco and ends up in storage.