Hello,

What do you mean with "lost"? Have they just disappeared? If yes, maybe your account has been hacked and there's nothing we can do in this case.

I got same problem just few minutes ago. I did 30x auto battle on ice golem, when i back suddenly all artifact is disappeared. Then i close the game and launched it again everything is back to normal. This is really scary. 

Yeah, its just a visual bug that has been reduced to minimal occurance rate but still happens at the time. Restarting the client fixes the issue. The only way your gear "disappears" is if your inventory is full and mailbox is full as well; in that case, whatever you get trully goes into void. So always make sure you have slots in inventory and inbox free, especially if you re using autoclicker for extended period of time (which is by the way, not officially supported by Plarium.)