Use one block for all courses
By default, Level Up XP keeps a different record of a learners points for each course. In order to gather experience points from all the courses a student is participating in, the admin setting Where are experience points used? must be set to 'For the whole site'.
This setting is located under Site administration > Plugins > Blocks > Level Up XP > General settings. Once set, any block newly or previously added will start displaying the experience points earned in any course.