Why is Turbotax rejecting my EIC?

I'm 21... no kids... $17390 wages... non-student

I've triple checked my boxes, and can't find the error.

After the rejection, I get this explanation:
"Hmm... looks like this explanation isn't available right now. We're working on it for you, so please check again later."

Irs.gov says with no qualifying child you can take the EIC if "you earned less than $21,430 ($27,380 if married filing jointly)", and Turbotax's own support section agrees with the Irs.gov definition.

I also tried two other online tax preps that allow me to claim it, but I would prefer to keep my business right here.
Thanks for any guidance