My son was in the same situation. In 2019 I claimed him as a dependent. He did not receive any stimulus checks because of this 2019 filing status. In 2020 however he was an independent because he was no longer in college. When he filed his taxes using Turbo tax, it recognized that he qualified for $1,800 stimulus and this was considered a credit. He received a federal refund and an additional 1,800 due to the stimulus PPP programs.
No need to file any other forms, since you are getting this by filing your taxes.
