I have inserted a reference image (a png file)

I draw a polyline over it, but it is appearing behind the reference image. When I right click on the reference image and go display order -> send to back, it is still not going to the back.Similarly, bring to front on the polyline is not putting above the reference image. This makes it pretty impossible to trace over imagery.

However, when I print the file the polylines are displaying over the image and the image has indeed gone to the back. It is just in the display on the screen in model space and in paper space it is not letting the polylines draw over.

Using latest Mac release (downloaded yesterday) on a macbook pro.

Thanks

Wade