Hi Simon,

There may be a glitch.   Suggest you report your concerns via the "Report a problem button" top left of the lesson.

Jim

You need to provide an example for us to give you meaningful feedback.

Just to make sure, you did read the second half of the exercise, where it says:

To emphasise that a (recurring) action in the past has now stopped happening with depuis, you can also use Le Présent Indicatif  with ne ... plus (not any more) instead of ne ... pas.