When an external LMS links to problem components in a graded edX subsection, the edX system grades the answers to those problems, and then transfers the grades back to the external LMS.
By default, the edX system aggregates grades for units and subsections every 15 minutes.
To change the interval for returning aggregated grades, follow these steps.
edx/app/edxapp/lms.yml, change the value for the following
LTI_AGGREGATE_SCORE_PASSBACK_DELAY = 15 * 60
You specify a time value in seconds.
Restart the Learning Management System processes so that the updated environment configurations are loaded.