This issue was resolved as of ~3:20pm PST on 7/5/2019. If you are still experiencing this issue after that point in time, please contact email@example.com.
We have found that there is an issue with review tests/exams not showing a success message properly after users complete them. Users are also not receiving test results via email after completing, as usual. We're actively working to resolve this. In the meantime, your results are recording to our database and can be found by following these steps.