My Adobe CC account says I have 2 devices activated, both say a Macbook Air (i only have 1 Air), both say they were activated within 4 days of each other from back in June 2020 (i've had an Adobe CC account for years). One says 'MacBook Air on MAC', the other says 'MacBook Air on OSX'.
Getting a new Mac soon so need to know which I should deactivate??
Maybe it's cos I also have CS4 on this machine? (installed from a CD, not the cloud).
I have no idea why they both say they were activated last June.
Since you have One Mac and currently you are unable to trace the 2nd mac or do not understand which other Mac account has the license activated, in this case I would request you to try the Option "Sign out of all computers" just below the Error/ Warning message. That way your Device count will be reset and you may simply Sign out from the Creative Cloud App on your Mac and Sign in back and this will activate the license on your Mac as 1st device. When you have your 2nd new Mac, that will be counted as the 2nd Device.