This is part of a few enhancements requested by a group of users with various accessibility needs.

Problem: When navigating the activity completion report, upon scrolling horizontally to the right, the user's names are no longer on the page, and you lose your ability to know which checkmarks correspond with a certain user. This is similar to an issue that was recently fixed in the gradebook as part of UX improvements.

Impact: While this is challenging for all users of this report, it is particularly challenging for users with limited mobility relying on keyboard navigation (needing to move back and forth on the page to reveal the names while visually scanning completion checkmarks). This may also be considered a failure of Success Criterion 1.4.10 Reflow (open to interpretation) because you are losing the names of the participants that help you make sense of the checkmarks unless you hover. (Note: I'd like to compliment the screen reader experience in NVDA, however! Nice job!)

I did not mark this accessibility as I will leave the person intaking this request judge if it may fit there.