I don’t have screenshot for the gems but I did all daily tasks for yesterday and got the gift box I merged my gems and collected it

As for the halloween chest, here you can see that the chest has been claimed but I couldn’t open it since I’m still trying to get the key

I’m playing on crazygames, I play on pc at work but I changed and played on crazygames on my phone back at home, when I opened up the game at work just now both halloween chest and collected gems are gone

But progress is kept and saved

I would have experienced the same issue. The gift that you get after completing the missions disappeared and I did not even pop the bubble for it and it just vanished without me getting to redeem it.