“When you try to associate another Apple ID with a device that was already associated, you might see a message that says, "This device is associated with another Apple ID. You cannot associate this device with another Apple ID for [number] days." Depending on when you associated your device with your Apple ID, you might need to wait up to 90 days to associate the device with another Apple ID.” [1]
The issue is that one shouldn’t change accounts all the time when using certain services, such as Apple Music. Your device, your one account, and stick to that.