Sometimes I get downvote with a good comment so I delete my post immediately. And my post is not aged more than one hour. So the downvote let's me loose 2 reputation and when I delete it I loose 2 more reputation.
Can I know why that happened?
These 2x -2 reputation changes were from suggested edits you had to other posts which were then deleted:
That's intentional, since presumably they were bad edits. I tend to agree the above 2 fit the intention, neither fixes the post.
What's not intentional is the delay in recalculating reputation (triggered by those other deletes) or not displaying it. I'll confer with the team and see what we want to do here.