Itt not quite bug (probably), but i found several stone spheres, randomly placed in world, no matter the biome, like someone with Worldedit shoot them randomly.
Theyre quite annoyin to eyes, thats all there is to it.

Is this only Certain biomes or all?

i saw it in few biomes
thsi one and plains, then one with cherry trees, and one with big spiky mountains. ill try to look around more
i saw one even in ocean

Talked to my fellow Developer and They said this isn't from our mod which confirms my thoughts as well.