Starting with version 1.2023.2 (which is online as a beta), PlantUML handles differently namespaces and packages.
There won't be any difference between namespaces and packages anymore: both keywords are now synonymous.
The drawing is slightly different, because we now also draw intermediate packages. Note that this is not a final choice, it depends on the feedback from users.
Packages now involve the definition of a namespace, as in any ordinary programming language. The default separator is the dot (.) but can be changed using the
set separator X directive. You can also disable namespace management using
set separator none, in which case you get back a behavior similar to older versions of PlantUML.
The parser is also slightly more strict. You now have to declare an element before adding a note on it, for example.
Usually we try to make improvements that don't break backwards compatibility. Here we were forced to put in a more consistent behavior, which unfortunately might break your old diagrams. However, the addition of the
set separator none should fix it, if necessary.
That leaves the drawing part, and let's see how you react here. You can open issues on github or react on the forum, depending on which tool you prefer.