Reported, but SC deny there is a glitch.
I have again lost another 5 diamonds to the sea chest glitch.
After reporting the matter to SC, I was told there was no 'glitch' and that they needed screenshots in order to verify what had happened.
Of course, there were no screenshots TO send to them because I wasn't expecting it to happen. Since that time, I have been religiously screenshotting every single time I get an open sea chest and a prize. Finally today the glitch happened. I have now sent SC a shot of the town I had been in showing my diamonds, plus one on my return where there are 5 missing.
Do I need to take bets on the fact that they'll tell me I used 5 diamonds to open the chest? Cynical, moi?