I am using the default sky sphere that is created when you create a new level (BP_Sky_Sphere).
I also have default rendering settings (DefaultEngine.ini) and am using Epic scalability settings (and 100% texture res scale).
I debugged this for a long time and finally figured out that if I delete some of the other actors that are taking a lot of memory then the stars/clouds appear clear.
I figured this out after looking at the Size Map.
Is my gpu running out of memory? Or what is going on here?
Blurry stars:
Clear stars:
Edit: The difference between the clear and blurry clouds is much more noticeable.