We are currently aware that the chests keep randomly breaking. We are still trying to figure out the exact cause (so far we have not found an exact cause after several ideas). Bas has been close in touch with the developer to see if the issue can be fixed.
Regarding you losing 2 of your chests, if you have any proof that you had 2 chests before, please open a ticket with the proof and we'll handle it there.
Thank you again for your continued support while we try to get this fixed!