Thanks @RDAOU, that worked (but I had to load a different family (View Title.rfa) as View Title (AUS).rfa could not be found in the Australian content folder C:\ProgramData\Autodesk\RLT 2022\Libraries\English\Australia\Annotations\Symbols\General)
What's interesting is this seems only to affect projects created with the template DefaultAUSENU - Loaded.rte (other templates included in the AUS content pack, such as defaultAUSENU.rte which also has this view title). They look different and can be edited.
Note, I ended up deleting the entire Family and then loading View Title.rfa and adding it back to the Viewport Title w Line.
Note 2, I also found a BIG bug in the DefaultAUSENU - Loaded.rte template: The New Construction phase has been created BEFORE the Existing phase (which a problematic as you can't reorder phases). DefaultAUSENU.rte and the other templates that come with the AUS content pack all are correct - ie New is AFTER Existing.
