Affects Version/s: 20w21a
Fix Version/s: None
The pattern seems like a strange formation of stone which repeats itself throughout the map.
When i go to those locations where the stone things are meant to generate according to the map, i see only regular minecraft terrain with no exposed stone at all.
I have tried it 3 times in multiple snapshots ( same world ( survival )).
in the first try, i made a map in a version which i honestly don't remember, but it was around 20w12a, and it generated those weird stone things i mentioned. When i did so, i extended the map in a cartography table to the maximum, so when i generated the map then it did not reveal the full map. In a later version i came back to the map and generated other parts i didn't generate back then, and they generated normally.
the second try was in 20w20b. I generated the map yet again ( though not for the same area ) and it did the weird stone things.
In the third time, i tried in 20w21a and it generated the exact same stone structures.
I am leaving a screenshot below