Hi,
The problem comes from the IRI name of your ontology. You named it "C:/Users/R/Google Drive/PhD/PhD_ONTO-GRAMMARS/00_DEVELOPER/00_Bottle_Ontology/test_geom.owl". However, many tools (including Protege) expect the IRI of an ontology to starts with http://
You should also remove the space between Google and Drive.
I renamed it "
http://test.org/Users/R/GoogleDrive/PhD/PhD_ONTO-GRAMMARS/00_DEVELOPER/00_Bottle_Ontology/test_geom.owl", and the data properties values appear as expected.
Notice that you do not need the IRI to correspond to a real URL available online : Owlready (and other tools) use local copies when available.
Owlready2 accepts a filename when creating an ontology (get_ontology(filename)), but only for loading the ontology. When .load() is called, the IRI is replaced with the real IRI extracted from the file.
Best regards,
Jean-Baptiste Lamy
MCF, LIMICS, Université Paris 13