Every time I buy a ruin the game reloads. When I reboot, no ruin and my gems are gone. Anybody else have that problem?

Hi and welcome to the forum :)

you will have to send a support ticket to sp about this so they can refund your lost gems and solve the problem
this was posted in dragon city section but i feel you mean ML -- not sure if DC has ruin too so this is how to report ML bug
https://forums.socialpointgames.com/topic/30/how-to-report-game-problems-to-support
DC bugs
https://forums.socialpointgames.com/topic/80/how-to-report-game-problems-to-support