Learning Assessment does not record completion even though user gets passed message

For learning assessments we find that our learners can get a message that the assessment is passed, but the score and pass are not recorded in learning. This can happen over and over again. Clearing the cache usually resolves the issue. This happens very frequently, so it would seem that something is perhaps not set up correctly. Learners should not have to clear cache every time they need to take an assessment.

We are not in Redwood. I'm hoping it will be better in Redwood, but I recently saw someone having a similar issue there as well. Any thoughts on how to correct this?