Most likely what happened is you attached the lane accidentally to the assembly baseline and not the median. You then moved the lane subassembly to the correct location. When you do that, it's still attached to whatever it was originally attached to but now with an offset. Grab your lane (and everything left of it for the left side) and on the ribbon choose the command MOVE. Don't use the AutoCAD MOVE, COPY, or MIRROR command unless you don't want to change what the subassembly is attached to.