Experienced the exact same bug earlier today using cut copper slabs. Place one targeted to upper side of a block, it goes lower. Next slab targeted to same spot goes upper but one block out further on that side. Hard to make a row of upper slabs for a project. No problems found with smooth stone, polished andesite, deep slate brick, or red nether brick slabs.
Experienced the exact same bug earlier today using cut copper slabs. Place one targeted to upper side of a block, it goes lower. Next slab targeted to same spot goes upper but one block out further on that side. Hard to make a row of upper slabs for a project. No problems found with smooth stone, polished andesite, deep slate brick, or red nether brick slabs.