here is an experience i did it today, i have a mission thats gives gems:
- destroy 10 monster (5 GEMS) "so i share it"
for 4 hours no one want to help me to finish it, why ??!!
i think you know the answer (komoney).
Yesterday and today I have been accepting and doing all gem missions the instant it is shared.
Except for my own destroy 10 monsters mission there wasn't another one.
So stop lying and saying you shared any.
I'm currently getting so few gems. This event is so tiring that I only do the PvE missions on auto or the PvP with an AFK deck where I don't use a single card.
You enter a game in PvP and you let the timer run out.
Since Surrenders don't count for rewards this is one of the less tiring way to complete gem missions. Sometimes your opponent gets bored and they quit before the timer runs out.
I don't know if anyone reported me yet. But usually I would say your opponent is happy for the free win and won't say anything.
Plus losing on purpose without cheating is nothing illegal that goes against any rules whatsoever.