Has anyone else had experience with UE4 being flakey?

I can’t really put my finger on when it happens, but I’ve had multiple instances of one of the following:

  1. I’m working on my game, I launch it hundreds of times during development and it always works. I close out of the editor (for whatever reason) and come back in and now it doesn’t work “properly”. It runs, but it does something funky (like right now it’s play ALL ambient music from ALL of my levels simultaneously and it’s not displaying my menu anymore).

  2. I’m working on my game, it was working but now all of the sudden it stops working “properly” (for example, the menu stops appearing). But if I exit the editor and come back in and hit play it works.

I’m wondering if it’s not some uncompiled Blueprint somewhere or something? Is there a way to “recompile all” blueprints, or does this sound like a bug?