there is nothing to fix; 17 year olds are not eligible for the stimulus. you did everything correctly, 

anyone over the age of 16 who was a dependent on someone else's tax return was not eligible. 

anyone  who was a dependent on someone else's tax return was not eligible for the EIP .

Anyone over the cutoff age who was a dependent on your return was not counted toward your EIP.

@fanfare - 

Anyone over the cutoff age who was a dependent on your return was not counted toward your EIP.

directionally correct and I agree, but technically, anyone listed as eligible for the "child tax credit" on the face page of the 1040 is counted towards EIP. Yes, that is typically anyone under 17, but if you are permanently disabled and dependent on someone else for more than 50% of financial support, regardless of age, you are eligible for 'child tax credit' status .... there is an exception to ever rule! 

@NCperson 

I'm not sure what you're trying to say. Some one could interpret   "....if you are permanently disabled and dependent on someone else for more than 50% of financial support, regardless of age, you are eligible for 'child tax credit' status .... " as meaning an over 16 person is eligible for the Child Tax Credit.

A disabled adult child can  be considered a "qualifying child" (QC) for dependency and qualify the taxpayer for EIC, but if that QC is over 16, he does not qualify the taxpayer for the child tax credit.  The taxpayer gets the $500 Other dependent credit, instead. 

@Hal_Al - if you follow the thread, the comment was specific to EIP and nothing else.