Titan Gaia shows up twice in the list of Objects in the Editor, and both versions are slightly different in game. One appears normal, whereas the other does not show the Divine Immunity ability or have a history description. It doesn’t recognise them as the same unit when selecting them together. I have no idea what’s causing this.
EDIT: Gaia from AOTG has the same Editor name as SPC Gaia, making it difficult to tell them apart. She’s the only duplicate AOTG unit that doesn’t have a unique Editor name.
Additionally, AOTG units have no history descriptions. The duplicate ones could link to the same descriptions as their standard counterparts.