Bug I think

So I have noticed that my gems keep going down but I havent been spending them. And when I complete the missions they give me like 1 or 2 gems and it doesnt even say I got them. Like today I started the game with 40 gems and then got off and when I got back on I had 31 gems. I never spent any on my building to make them go faster. I think its a bug but Im not totally sure. Please fix this and I will give it 5 stars.

007Studman about Vikings Gone Wild