I received my curtain rod on Tuesday, Jan.26th and was well pleased with the appearance.  It was exactly what I wanted.  However, I cannot get it to tighten up when I try to install it.  I only have my fabric curtain on this rod and not the vinyl, which is on a different rod behind the one I bought from wayfair.  It keeps falling down and the least touch of the curtain.  I am getting a little discouraged.  What can I do that I haven't done.  I have followed all installation instructions each time and it still won't tighten up.  Does it make a difference that it is on a shower that is tiled?