If you put any block on top of them, they revert to their normal form. Relogging does not fix the issue.
Environment
OS: Windows 10 20H2 (19042.868)
Java: 16, not included in launcher
Others: Using the datapack that enables the caves
Seed: -8732676757155916834
Coords: -386 67 8752
Linked issues
Attachments
Comments 2
Duplicate of MC-132306.
These are
minecraft:grass_block[snowy=true]which have snow textures on the side. These should normally have a snow layer on top of them.