That's right.  Blame the kid, don't blame the politicians who wrote the law.  And where does it say he did not have tax withheld?  From what I have seen, the choice is either zero or ten percent -- higher amounts are not an option.  

And how much was your PPP grant?

Give them a year, and Congress may get around to fixing the Kiddie Tax rules so that unemployment is considered earned income.  I would delay filing the return and tell the students to call and email their members of Congress.  There are still a few journalists left who cover good tax stories, also.