Worked on improving collision-check reliability in the moveit/moveit2 repository by addressing stale data issues in the Allowed Collision Matrix (ACM). Focused on ensuring that ACM entries are properly removed when collision objects are deleted from the planning scene, which prevents outdated collision information from affecting motion planning results. Implemented the fix in C++ and added a regression test to verify that ACM cleanup occurs as expected during object deletion. This work leveraged expertise in collision detection, motion planning, and robotics, resulting in more accurate and reliable collision checks for dynamic environments where objects are frequently added or removed.