Missing connection UUID not written to .nmconnection
When a .nmconnection
file is copied to make a new profile, it should have a unique ID and UUID to avoid confusion between the two profiles. If UUID is removed from the new connection, NM could (and I believe it used to?) generate a new unique UUID since it is missing. Ideally, this would be handled at startup where UUIDs are checked for uniqueness (which was added in v1.2 according to NEWS).
I think this is more of a bug than an enhancement since UUID is needed to identify connections in basic NM operations, /var/lib/NetworkManager/seen-bssids
being a random example. Also I suspect that some of the described logic was already present sometime in earlier versions and might only be broken.