Those numbers should allow you to claim the credit and none of the grants are taxable, to him.
"Is it his age? "
Probably not. Age 24 is a turning point for being a dependent (rule change, not an automatic disqualification). But once he is your dependent, the education interview is the same.
Make sure you have the latest update. Education change was included in yesterday's update. Yes, deleting education and starting over may be the solution.
