Do you mean when you add/remove or change one block it affects every block (all blocks become the same)? Or describe the exact repro/behavior (what you click, what happens, screenshot or console output).
If it's the "one change affects all blocks" issue I can push a fix now (common safe fixes: clone colors when building geometry and ensure vertex order/winding is consistent). Which would you like me to apply, or share a short repro?