Cheap contract emulsions like the above screwfix product have caused me more problems than i care to mention.
Not picking fights here but 30+ years of experience have made me hate them , especially in bathrooms and en-suites.
For example, with Dulux Supermatt which is a more expensive version you can almost cover bare plaster in one coat with a good roller, which is what many disreputable contract painters do. A few years down the line subsequent coatings will gleefully come away from the wall in sheets, especially if you’ve wallpapered over them.