Unusual Sketch Problem

Hi everyone,
One of my students is having an issue with sketching on the XY plane. He has one sketch on the plane. When he tries to do a new sketch, the moment he tries to put the rectangle down, a different sketch appears with dimensions on it. It turns out that the sketch which keeps re-appearing is the first sketch that he did. None of the other students has this issue.

Hello Carl,

Would you have an example to share?
This helps understand the problem.