Son graduated last May and started working September, filed his own tax for 2020, can I still list him as dependent?

[changhsuliu]

I got rejected but based on the tool I used, he was at least 5 months as a student and paid for the education, housing, and food, so he should be eligible as dependent even he filed his own tax for 2020.

So how can I claim him as dependent?

Thanks,