Refer: https://helpx.adobe.com/x-productkb/policy-pricing/activate-deactivate-products.html
If the option to sign out is disabled.
Try closing all adobe processes from activity monitor.
Activity Monitor: Quit a process
Go to user library and rename OOBE folder.
Relaunch Creative cloud.
Let me know in case you still face challenges.
Regards
Megha Rawat