Put together a puzzle.
Or go on a walk.
Or knit or paint your nails or wash the dishes (that’s what Agatha Christie did) or do something with your hands which enables your mind to wander freely.
There are, simply, some aggravating moments in creative writing when your brain gets frustrated and needs to chew on a plot a bit before committing to any more words.
Or, sometimes, your characters misbehave and take you to a new place you never anticipated visiting, and you need to get acclimated with your new surroundings in the story before actually writing about it.
Whatever the case, give your brain a break. Get busy with your hands, and daydream a bit.
You’ll write more later.