Just repainted our bedroom, over the existing paint.

I had to fill and sand a few bits, so when i had some spare Dulux matt white left after doing the ceiling I figured I'd put a few coats over the filled/sanded bits to make them even smoother and seal any exposed plaster.

When that had dried i put 2 coats of dulux light&space emulsion on the walls. 24 hours drying time between coats.

The light&space stuff has crazy-pave cracked just over the areas where i put the white emulsion but nowhere else.

I figure the white emulsion has somehow sucked water from the light&space emulsion, a bit like an unsealed plaster wall would do.

What do I do now?!!

Sand off and repaint (would I need to reseal the wall?)
Leave a week to dry completely and then paint over?
Just paint over with watered down light&space emulsion, then another coat on top

Clucking bell I hate painting!!

I've seen this happen before, but only with different brands of paint.
Never used light and space, is it a soft sheen type? If not, you could probably sand it back gently and touch up.
Other way is same through the white and coat with dilute light and space then redo the whole wall