Gem auto leveled to 20

Howdy, was preparing my gems for my hungry loop, and one of them auto leveled to 20 when i went through a portal. clicked the portal and then got the achievement for leveling a gem to 20, now cause the gem was in use, and wasn't in the hungry loop, i didnt get it. this is rather annoying cause now i need to spend another 12 hours grinding another gem to 20.