Illustrator - objects can be clicked on but colour/stroke etc won't appear

Hello!

So I'm working on a file in illustrator and for some reason some of the objects have randomly decided to not appear. I can click on them, and can see them on outline view, but not in pixel view. They appeared before, but now when i make new objects they don't appear either.

I've fully updated illustrator, so not sure if it's a problem with the new update?

Have attached a couple of pics if that makes more sense.

Thank you!