As I said in my comment, the fact that the names change is perfectly normal and expected behaviour.
This is why you'll find nowhere in Ubuntu that refers to the drives by these names, instead fstab will be written in the form UUID=... which do not change.
As I said in my comment, the fact that the names change is perfectly normal and expected behaviour.
This is why you'll find nowhere in Ubuntu that refers to the drives by these names, instead fstab will be written in the form UUID=... which do not change.