Yes I don't understand why it finally corrected the xml file after I tried different versions. It seems to work now.
As I already said, I am sure I had a similar problem in the past. Ekos reads an xml file but the driver gets conflicting information,
so is technically crashed or broken and is unable to recover.
My issue was that my camera was on a system that I had frozen at kstars 3.5.8, and I simply copied the xml file across to the new system
to preserve gain/offset etc. A shortcut which proved a not to be.

I see. Ok, that's in the rear view mirror now and the only thing we need is some clear skies!