I have been experiencing the same frustrating problems with Creative Cloud Desktop App after upgrading to version 1.2.1.260. I went through all the suggestions I found on this forum. Reinstalling the app, using the cleanup tool, removing the opm.db file etc. I even finally performed a complete fresh reinstall of Windows 7 64 bit. I managed to get it running, but the CC Desktop kept disconnecting. After reboot, but also after closing e.g. PS it disconnects.
But then I tried something which seems to work uptill now since a few days. I'm not sure it's a solution, or a coincidence, but I configured my firewall settings for the programs related to CC. I'm using Avast Internet Security. I set it as 'fully trusted' (...) programs. Since then, a few days ago, I have not lost the connection once. (Fingers crossed....) This might indicate there is a conflict with the firewall. I cannot explain why this works, but perhaps Adobe Tech can check this out and correct it in a future update of the app.