Railing - extra line in plan

Hi, I'm getting an extra, third, line that I don't want when looking at my stair railing in plan. See attachment. I looks like a second railing but it doesn't show in 3d view.
Also, I've adjusted my railing supports but they wont stay adjusted. They just snap back to the original location. And yes, I did unpin the supports.

I think nobody could recreate your problem, I too tried to do a stair and railing, and there is no third line.
Could you share the prj. file with just the stair and railing.