Grass blocks generated under ancient city center redstone room

The bug

The ancient city center redstone room generates with grass blocks underneath.

To reproduce

Default world type, No generation settings, Seed is -9107471108583759252,

Cords are /execute in minecraft:overworld run tp @s -922.56 -47.45 467.00 -671.29 27.13
No data packs installed
 
Alternative steps to reproduce this are found in this comment.