Has this issue been resolved? I’ve looked through the archive post and saw some mention that Code.org was looking into this. The post are over two years old. Still having an issue with this.
Traditionally only one unit can be assigned to a group at a time. Students can still access the previous units even after a new one has been assigned. They may have to scroll down their dashboard to find it or search the curriculum to access their past units. I found an older support article about this topic. The content is still accurate, but the screenshots are a little antiquated.