Matt emulsion (or flat latex) will not cover
I have prepared the walls of a bedroom with sugar soap (a cleaner used prior to painting) which is what I usually do first.
On applying my first coat of Matt Emulsion (flat latex) by roller the paint is 'skidding' and doesn't seem to be adhering to the surface.
The walls were previously painted with a cream coloured matt emulsion about four years ago and there were no issues at that time.
I am using Wilkinsons paint on this occasion; having done so in the past and being very pleased with the result.