This may not be valid given both of these were added a lot earlier than 1.17. However, 1.17 was the version to introduce an inconsistency, hence why I'm reporting this.
In Building Blocks, cobbled deepslate is placed directly after where deepslate is. However, this is not reflected in cobblestone's placement, which sits much farther from the stone it is derived from.
Duplicate of MC-1797.
Neither cobblestone nor stone have been added in 1.16 or later.