Lost progress, but just certain sections?!?!?!?

After the update I notice some of my progress is lost. Sections that I know I have completed are not checked anymore. Can I have this fixed or do I have to go back and redo these sections???

Many lessons were added, especially to early parts of the curriculum, and some lessons were reordered. This means that there will be challenges (or entire sections) that are unchecked lessons showing up among your checked ones because they are new.

Yes, even though I have completed many challenges in different areas.
It shows green checkmarks but when I open the challenge, the code is somewhat different.

So I think you either leave what you have already completed or you need to re-complete the challenges.

It’s true that some of the challenges themselves have changed. These are usually improvements to do things like make testing work better or to make the lesson a little clearer. It’s totally up to you whether you want to redo them. If it’s a lesson that you found particularly challenging, then trying it again might be a good mental practice. Certainly not a requirement though.

Awesome!!! Thank you!!!