you have to paint a layer of sealer then paint 2 coat of top coat, paint ceiling follow the same way with painting walls, then you wont have powder issue

i recommend jotun easy ceiling or nippon perfect white, but you can use any paint that is better like easy wash or even jotun sense, as long as not those cheap maxilite or jotaplast

not painting ceiling with good paint is the cause of fungus infection and powder falling issue