This break point or node thing has always been a PITA. Pro Tools creates them in a very useful way. Nuendo either doesn’t create them, or deletes them, if it considers they are unnecessary. Because of this, copying whole chunks of multi instrument automation is a bit dicey in Nuendo, unless you are very, very careful, whereas in Pro Tools it is flawless.
FWIW I brought this up years ago and was told that the disappearing automation points were by design, and therefore not a bug. I hope that the programmers look at this again and at least make it a Preference of some sort. It would be one less reason to mix in Pro Tools, that’s for sure.