This may be one of those fields that cannot be changed after a user has completed the test. Same as if they were in progress.

What @lrnlab said is 100% correct - you can’t change that value once someone has completed the test itself. Doing so would bust the previous scores as let’s say someone got 18 out of 20 correct and you had it was numbers originally so it reports 18 as their score. If you now change the passing to 80% for example, that person’s score is going to show as 18% now. Docebo doesn’t allow that for this reason. 

The only “workaround” I’ve found is to hide your current test in the course and make a new one and set whatever values you want so it reports the way you want going forward and whatever has been attached to the existing one will remain for historical purposes.

Of course, the workaround of creating a new test with different scoring creates a new problem if you have multiple scorable items and need to average them.  The best answers would be for Docebo to allow you to change the scoring method and recalculate the results, or for you to be able to limit the date ranges per test that count toward the average.

I’m not sure I understand why Docebo couldn’t support this- the underlying raw scores are stored, so it seems like a display question only to show 18/20 as 18, or 90%, not a score integrity issue. I’ve worked in several other major LMS systems and they all supported flipping back and forth (or displaying both optionally).

@sgary is correct, this should not be an issue. The raw score and the total points are stored regardless, just allow the option to be changed and in reporting report both: one cell for points received, one cell for total possible points, one for percent. 
When working around this flaw, how should I import the user completion data most effectively to the new test. I have a duplicated batch, but now I need to bring all of the users’ answers into the new set of tests. This must be done for reporting purposes.