Courses uploaded in 2019 are getting sorted as if they were uploaded in 2018 (i.e. for me, the new course appears at the bottom with the Jan 2018 courses) when the 'Sort by: Last Updated' option is selected.
There appears to be an issue with sorting any courses uploaded in 2019.
Thanks for the report. We did have an issue with the sorting of the dates, but it has since been fixed.