So I saw a treasure chest after beating a monster and I was like "Yay!" I took it, and kept moving on. But then I went back to where the chest was (to go back to the portal) and even though there were no chest there, I still got a second treasure.

Well, considering there were two bosses really close and that I found only one chest, I was wondering where the second went but I think I find it.

To check if it was not a bug like "go to this case and get a reward everytime" I tried to go back and forth, but I couldn't take any more stuff.

I can confirm that this happens - I've only seen it happen once though. There were also two bosses I beat, but only one chest. Moving over the empty spot a 2nd time gave me a 2nd chest.

I've also found some missing chests when checking water squares around where the chest should've spawned - This happened maybe 2-3 times.

Edit: Actually I've been paying more attention, and this has been happening every time there are two guardians back to back and a "missing" chest. Also the island always freezes after the 2nd chest pickup, and I have to refresh.

The island freezed as well for me :S

Hopefully Angel will resolve this.

Thanks for reporting!

We're working on this bug.

Sorry for the inconvenience.

This one should be fixed with the last update.