I am sure you remember there are Preferences and Design Properties in Data Modeler. Preferences affect all the designs in a Data Modeler installation (in that computer) whileas Design Properties affect only that design they are defined for.
Now in Data Modeler 17.3 you can find those Design Properties also under Tools menu by a name Design Level Settings:
These are the sames you can still find under Design Properties too and you should definitely check them (either under Design Properties or Design Level Settings), because they are important.
P.S. You might be interested in this too: helifromfinland.blog/2017/10/13/default-system-types-directory/