I've noticed that the aria-level is not being set to the values set in the authoring tool for the box menu.
Aria level should be set to level 1 but it's property is invalid (aria-level="course"). It is being announced as a level 2.
I'm not sure if this is specifically a box menu problem as I had a similar issue with adapt-tabs recently too :)
If anyone knows a quick fix that would be ideal.