I think this is a Gull-Winged Tern, based on the Grey upper wing and more robust body shape vs the Australian Tern. The bill reminds me of an Australian Tern though. It just shows how hard Terns are to accurately identify. If anyone has any input into this, please feel free to contact me.
https://ebird.org/species/gubter2
https://ebird.org/species/gubter2
