Coordinate System Problem; Kertau RSO / RSO Malaya (m) (EPSG:3168)

Hi, I've got problem with coordinate system (Kertau RSO: EPSG 3168). The potential position (yellow icon) is far away (approx 50 meters) from actual coordinates (blue icon) on ground.

It also happen for coordinate system GDM2000 / Selangor Grid (EPSG:3380).

Anyone can help me for this?