Completed projects sometimes have missing lessons

Sometimes when I log back in, I notice that some previously completed projects have a “hole” or missing step/lesson (if that makes any sense…).

See picture below:

How do I prevent this from happening ?

It happened to me too but it doesn’t happen anymore after I restarted my computer, maybe you need to reset your device, In the end I ended up doing it and it didn’t happen anymore :grin:

It is likely just because a new challenge step was added.