Assign Custom User Role to Membership

I created a custom user role using the User Role Editor plugin. I want to automatically assign this new role to members when they sign up using Memberships 2. I installed the add-on "Member Capabilities" and added my memberships to that new role. But new members are still only assigned the "Subscriber" role. The add-on doesn't seem to have any effect on current or new user's roles.

btw, I found some old threads on this subject but they all talk about modifying "Access Levels" which I believe is from the old Memberships plugin.