Why did you put it on sauté to boil before you put the lid on. That defeats the purpose. I don’t know if that has anything to with why the broth leaked out.
You should’ve put the bones, filled with liquid below the fill line, then put the lid on and set it for 2 hours on high pressure. It would take some time to come to pressure (normal), some steam would escape (normal) and the back cup would fill with condensation (normal).