yes it is drywall. I haven't tried painting the solid wall yet. If there is any wallpaper paste left on the wall will it go like this? It is patchy lumpy paint over quite a bit of the drywall. It seems like it is drying very fast & absorbing quite a bit of paint. Don't think there is any damp. If i mixed the paint with 10% water would this help?

Still got wallpaper paste on wall ?

Is this all over the walls? Because that is how paint reacts when the wall is damp.

what kind of wall is that ? is it drywall?

definitely should sand it smooth and wipe it clean before painting- you can still see all the bumps- it looks like you may not have gotten all the gunk off the wall

I have recently removed wallpaper from walls, sugar soaped and filled walls. I tried to paint using Dulux pure brilliant white matt but got terrible patchy results. It is as if the paint will not adhere properly to the walls and seems to dry very fast in places.

I then applied a primer/sealer with similar result (see pic). I am going to have to sand it down also. Does anyone have any ideas what i am doing wrong?