In the case of these UNI- vessels you are quite right, Denis, and they should not have been changed. I am sure that the changes were well-meaning, but if they are not reversed in the next few days, I will see that they are done.
What is painted on the ship is often a poor indication of the actual official version of the name of the ship (and occasionally seen painted in different versions at the same time on either bow, stern or bridge board). The true official version will be that recorded by the flag register, but few of these are publicly accessible. The most reliable publicly available source that we have is Equasis, which draws on several official sources as well as major databases such as P&I Clubs, class societies and particularly IHS-Seaweb, all of which occasionally have errors. But it is the best we have for vessels with IMO numbers, so it is right that we use that as standard.
For non-IMO vessels we use the best sources that can be found.