The only thing fuel gauge I've noticed on my CX70 is even when I put as much gas as I can in it the fuel gauge still doesn't read as full. It's very close but not quite to the full mark. I've tried it with the car parked at different angles with the same result. My Mazda app shows 99% as the max.
All the other Mazda's we've owned including our current 2023 CX5 do go to a 100% and show full on the gauge. Not sure if that has any relationship to the recall or not.