Approval workflow for specialization not working as expected

Summary:

We have created a learning specialization with an approval workflow, but even after approval has been granted, learners are unable to enrol onto individual activities. They see a message saying they need to request approval, but there is not visible button.

Content (please ensure you mask any confidential information):

We are trialling an approval workflow attached to a specialization. The learner requests approval and completes an enrolment form. The request is approved by a Learning Admin if the learner is suitable. This bit works as expected.

Once the approval has been given, we want the learner to be able to enrol onto all the activities in the specialisation, with no further intervention required from administrators. However, the learners are seeing a message saying 'You need to get approval to enroll into this learning', but there is no button for them to proceed any further.