Stone generates in Basalt Deltas floating island

The Bug
When traveling around a floating island buffet world of Basalt Deltas you are able to find overworld stone.

Replicate

• Create a Buffet World of Floating Island & Basalt Deltas
• Look underneath or to the sides of the islands
• Notice that Stone generates despite being a Basalt Delta were no Stone should generate

Here is the Seed and Cords when I found it
Seed: 4126225519331455930
Cords: 72 51 -15