Devices "migrated" but none work: C5 to C8-Pro

I only see one for sure ghost. The others are attached to devices, only have one neighbor and no route, so they sort of look like a ghost but are possibly just offline. If they are offline it might help to power them up. If they are already online, sometimes devices will never pick up neighbors and still work just fine, just might be oddball devices.

If you have a USB Z-wave stick and a windows PC, you could use that to remove it from the C5 first, then do a new migration. How To: Remove Ghosts using hub tools or a UZB Stick