Not sure what the problem could be. If you quit the LRCC desktop app can you add photos from your LRCC web app after logging-in from the link below?
If that works try re-launching the desktop app to see if sync kicks in.
If you click the cloud icon- top right – what connected devices are listed? Also check settings.
Have you tried logging out of the Creatve Cloud account as well as Lightroom CC Application?
(as there are no photos showing at all)
If the above suggestion of logging-out does not change anything, I can only suggest uninstalling and re-installing LRCC.
-Uninstall from Windows
-Re-start your computer
-Launch Creative cloud and install LRCC from the Apps tab.