I have been using the Photography option of the Creative Cloud (Photoshop + Lightroom + other stuff) since December. Has been working great. Suddenly, however, Lightroom does not appear in the list of installed or available apps, despite the fact it is installed and working normally. Computer is a MacBook Air 2012, 4GB RAM, plenty of disk space. My concern is that I am not receiving Lightroom updates.
Chat Now button near the bottom for Activation and Deactivation problems may help
I used chat as you suggested. Chat agent had me sign out of Creative Cloud (Choose the gear, then accounts, then Sign out) and then sign in. Lightroom appeared.