Assembly - Only allowing a right side construction

[rconnelly5HY6G]

I create an assembly and add a lane to the right and left. The issue is the left adds to the right. I can force change it to show correctly in the graphic but under the assembly construction It only shows subassemblies on the right. I have another file that works and when I import the assembly settings to the issue file the problem is resolved. What am I 'm missing???

[surafeltklt]

edit the side variable  to be left in sub assembly properties for the one on the left