Hi Fred,
I opened an issue on github regarding the LTI plugin not propagating its result tot the parent Course. I have set the Course's Learning Progress option Status is Determined by a Collection of Items and enabled the Course's Learning Path option Determines Learning Progress.
The LTI result is properly received (I used the Celtic test environment) but whatever the outcome, the Course status remains busy.
I tested this on Ilias 6.4 and 6.7.
Regards,
Rick