Why Did I Receive a 90-Day Visa Instead of a 30-Day One on My Visa Run?

The user shared their experience returning from a Chongmek visa run, where they intended to obtain a 30-day tourist visa but were mistakenly granted a 90-day entry on an American passport. They expressed uncertainty if this was intentional or a mistake, noting it was beneficial. However, commenters advised them that receiving a 90-day stamp was likely an error and recommended correcting it at immigration to avoid potential overstay issues.