LTI and Moodle

I have published a series of quizzes from a Moodle course as LTI tools, and my students have been accessing them through the university’s proprietory course management system called “Learning Suite” (LS).  I’ve created activities in LS that use the LTI “secrets” and URLs from Moodle quizzes, so that when students click on the activity in LS, they’re taken to the Moodle quiz, and then their grade is passed back from Moodle to LS. At least, that’s what was happening until about a week ago, when the grade passback feature stopped working. Students are still taken to the Moodle quizzes from LS, and they can still complete the quizzes, but their grades no longer get passed back to LS. The university’s tech support says they haven’t made any changes to LS, so some change must have been made in Moodle. The only change I’ve made was to grant another individual guess access to the Moodle course; I think I may have changed some setting under “Enrollment methods” as I was trying to do this. There are Could this have caused the problem? If so, how do I fix it?