Deep link doesn't work after completion

Summary

Why does the deep link to a course return a blank screen once the learner has completed the course?

Content

I have created a number of deep links direct to learning items which I have embedded into a sharepoint site. 

Here's what happens - 

Using the link the first time works fine - enrol - check out the learning content

Using the link the second time takes the learner to the content page but the view enrollment option takes the learner to a blank screen and you can't review the content again. 

The learning is still viewable from the learning history but I want learners to be able to use the deep links again and again.