FLIGHT SCHOOL QUALIFYING DEPENDENT?

My 23 year old Son graduated with a 4 year degree in July 2020.  He is now attending a Flight School full time, and is not working.  When I began to do my taxes using TurboTax for 2021, and imported my personal info from TurboTax 2020, the software again listed him as a Qualifying Dependent, and automatically listed my tax filing status as the previous year, HOH.  I am divorced, and per the decree, my Son is awarded to me for "Tax Reporting Purposes".  Is this correct, or is he NOT a Qualifying Dependent, and I'm supposed to file as Single?