I have two grade categories - Presentations and Homework with a 40/60 split. I have set up a grade book for" "Exclude empty grades and for most of my students, the % grade I see as the Course Total is lower for the unticked "Exclude empty grades". Logging in as one of my students show my view and their view is identical as long as they have completed at least one piece of homework.
However one student has done no homework at all and his whole category is empty. My view of the user report is 31% ( 78% of the section providing 40% of the mark) but his view is 78%.
Moodle version 3.5