Yup - ghosts are in the Z-Wave database and "come along for the ride" when you do a migration. In general Z-WaveJS has been very good about removing ghosts, and you can try again to remove it on the C8-Pro w/the Refresh>Remove buttons on Z-Wave details.
You could try the Z-wave UZB stick ghost removal process, but if "things just work" and your only issue is a contact sensor ghost then I'm not sure it's worth the effort.