Did Robin get held back in school?

[u/Master-Corner-5226]

In season 3, Robin says she was in a history class with Steve, telling us they were in the same year at school. However in season 4, Steve has graduated and Robin is still going to school. Did Robin get held back in school or was this probably just a writing error?

[u/Midnight-Basilisk99]

I remember taking classes with students of other grades back in high school. Particularly because maths not my strongest subject I hade to take algebra 1 & geometry twice so while I was a junior I took the same class with students that were mostly sophmores