I set 'genesis.json' like this.
It's 810,000,000 at decimal. But when I run the blockchain and start mining, the block gas limit decrease.
I'm using Geth/v1.9.7-unstable-a73f3f45-20191003/linux-amd64/go1.13.1
I can't find such kind of error examples. Do you know why and how can I fix it?