Cannot make progress on legacy code

Is it intentional that one cannot make any further progress on legacy code e.g. the Python legacy code ?

Though I am answering correctly, I cannot click on the progression button (it’s shaded in light grey as you can see).

I understand that this feature might save people from unintentionally going through the course and realizing that it does not lead to any certificate. Yet, it does not mark the point where one has stopped progression through the course, so maybe progression through legacy code should be allowed and indicate by other means that there is no certificate to earn here ?

Is this a step in particular? I have no issue in submitting questions there