What had worked for me in the past is:
Go to My Dashboard -> My Account -> My Connection -> <Scout’s Name> -> Scout’s Connections
My Dashboard -> My Units -> Unit Roster -> <Scout’s Name> -> Scout’s Connections
Then, assuming that the scout has already “started” (in Scoutbook) the MB for which I will counsel them, I modify my connection to include “Merit Badge Counselor” and select the correct badge.
If they haven’t started the badge yet, I add the badge by going to
My Dashboard -> My Units -> Unit Roster -> <Scout’s Name> -> Scout’s Advancement -> Start Another Merit Badge
I select the badge, then “Lookup/Invite counselor” to add myself.
That worked fine for me just now on a test case.