How to remove dots from clouds?

I am currently working on clouds using Ultra Dynamic Sky now.
However I’m having a problem on my cloud.

cd1
Whenever I look at the clouds or get closer to it, tiny dots scatter on the screen as you can see. What I expected was just smooth clouds. Especially at the last moment of this image, dots scatter even on the air where clouds don’t exist.
I’m assuming that this is not because of Ultra Dynamic Sky because this happened on every other cloud assets I’ve used before. I once changed my engine quality settings from high to cinematic but the dots couldn’t be removed. Why is this happening and how can I solve this problem?