The option in account and security for active sessions has 2 active sessions which cannot be deleted

@lively_painter6932 under that screenshots, I would click on the 'god mode' and 'End all sessions' button

This should sign you out of all devices globally, effectively removing all current active sessions except for your current one! 

Depending on how many there is (sorry, I can't see the full list), wait a few seconds. For good measure and most critical too, I would also clear the history, cache and cookies. Clearing the history, cache and cookies removes any old, potentially corrupted, or expired session data that your browser stored for the Adobe website. This forces your browser to perform a fresh, clean sign-in when you next access the Adobe Account page or use Acrobat/Creative Cloud, which helps ensure the new session is correctly registered and the old issue doesn't reappear. .

Now,, go back and open Acrobat (or the Creative Cloud desktop app) on the device you want to use. You will be prompted to sign in. Sign in with your Adobe credentials. This action will register your current device as one of the two allowed activations. Go back to the Adobe Account "Active sessions" page in your browser and check that only your current session is listed.