I've been experimenting with geode configured_features and noticed that they are capable of replacing bedrock. This should not be something that happens in normal gameplay.
To reproduce
Install the datapack TESTING.zip
Run the command /locatebiome lithoscene:salt_flats
Teleport to y=-5
Observe that the bedrock is being overwritten by the geode features.
This issue also happens without using a data pack, for example at this location (from MC-214107):
Seed: -115398801428600131
Coordinates: -430 0 -2429
Linked issues
is duplicated by 17
relates to 2
Attachments
Comments 7
Relates to MC-207457
Needs testing.
Can also confirm in latest (as of commenting) snapshot.
Snapshot: 21w06a (EDIT: found naturally without the datapack)
Seed: 4850489050736750011
Coords: -19865 -72 3787
I've also found it.
Snapshot 21w06a (found while exploring)
Seed: -2340302681446941398
Coords: -701 -64 -2544
The second screenshot shows that I've dug out a little area underneath the geode to show bedrock being overriden by the geode blocks.
[media][media]
I also found this on my own snapshot world