When you reset back to a previous level and start re learning the items in lessons, the Notes do not show. I know they still exist because if I try learning through an app (such as Flaming Durtles) it pulls in that information.
E.g. In Lessons for the Radical Boat it shows this
When viewing the radical itself it shows the meaning note
I believe this issue is present for all radicals/kanji/vocab but I haven’t thoroughly tested with all examples.