The system says 6.1 is up to date when I run Check for updates
… and it rightfully does so.
LibreOffice 6.2 is in the Fresh branch currently, while 6.1 in current Still branch. Only new releases from 6.1 will be shown in 6.1 (until 6.2 reaches Still status).
Download and install 6.2 manually from LibreOffice site if you want to upgrade.