Hi AdmireCha,
The message you've provided is mentioned on the site View and remove your devices that are associated with Apple ID purchases:
"When you try to associate a device that was previously associated, you might notice a message that says, "This device is associated with another Apple ID. You cannot associate this device with another Apple ID for [number] days." You might need to wait up to 90 days to associate the device with a different Apple ID.
This list of associated devices is not the same as the list of devices that you're currently signed in to with your Apple ID. You can find out where you're signed in on your Apple ID account page."
You may contact Apple Support directly to inquire if it's possible to address this prior to the 40 day period, or wait until that time has elapsed. No other actions other than reverting to the previously associated Apple ID can be taken to address this.
Regards.