When we're editing pages in lessons if we have a block that is configured to Display on page types: any page it doesn't auto-move to the left column when the lesson page is in editing mode.
When editing in other modules, including the edit settings page of the lesson module the block is auto-moved to the left hand menu to allow the center column expansion room. It is only when editing lesson pages that we see the block remaining in the right-column.
I've attached an example with just one block on page, but in our lessons there are multiple blocks stuck on the right, which makes accessing the content editing fields a bit of a challenge.
Although my screenshots are taken using a lightly customised More theme this behavior happens when using the Clean theme too.