Hi Peter,
please check if you have a mastery score in your SCORM manifest: https://docs.moodle.org/31/en/SCORM_FAQ#Moodle_changes_cmi.core.lesson_status_from_.22completed.22_or_.22passed.22_to_.22failed.22.
If yes, either remove it or remove the submission of a score when the test has not been actually run.
As Dan said, you can access the talk between your content and Moodle via the API debugging: https://docs.moodle.org/31/en/SCORM_settings#Other_Important_Settings, see Activate API debug and tracing (set the capture mask with apidebugmask).
HTH,
Matteo