Some (possibly all) of the Pale Mud related blocks from the Pale Bog biome appear to be missing the tool harvesting options that their vanilla counterparts have. For example, regular Mud can be harvested with a shovel and Mud Bricks can be mined with a pickaxe, but Pale Mud and Pale Mud Bricks can't. I'm playing on patch 2.4.5-Fabric on game version 1.21.1.

Screenshots showing the lack of tool icons (and regular Mud for reference):