Hello, I had a B-1 visa interview last week.

I got rejection.

I am a South Korean citizen. I had ESTA since last year.

I called ESTA and asked if I can use the existing one.

Different people talked differently but they say to re-apply with the answer of "yes" to "have you ever denied the visa...?"

I sent the new ESTA application and it was unauthorized.

It happened on the same day.

I read here that this occasion will happen only if someone is criminal. I am not a criminal.

Why is it so?

Can I re-apply ESTA later on?