Kepler 22b biome's probability

[cbls800]

I want to confirm, I compared 1.7.10 and 1.12.2, is there a problem with the rich ore biome in 1.7.10 that the probability of appearing is too low or impossible?

The rich ore plains is It was added in 1.7.10 - v1.9.6, and I tried v2.1.4, but even when flying in creative mode, I only seem to see various woods, pink deserts and gray-black wastelands.

And 1.12.2 added rich ore plains and corresponding plants in v0.1.5. I played in v0.8.0 and it is easy to find.