CVT drone and a flat spot around 40 kmh on a 2020 Civic ZX

2020 Civic ZX, 1.8 i-VTEC, 31,000 km, one owner, always serviced at Honda.

Two things I have lived with and want owner opinion on before I spend money.

The first is the drone. Anywhere around 40 to 50 kmh with light throttle, the car sits at a steady note that is louder inside the cabin than it should be for this car. It is not a rattle and not a whine. It clears the moment I lift or push harder.

The second is a flat spot at the same speed. Light throttle, and the car takes a moment to gather itself before anything happens. Full throttle is fine and the car pulls properly.

Gearbox oil was changed at 30,000 km with genuine fluid. No warning lights, no jerks, nothing else out of place.

What I want to know

1. Is the 40 to 50 kmh drone just what this gearbox does, or did yours get better after a fluid change
2. Has anyone found this to be tyre or engine mount related instead
3. If you have crossed 60,000 km on the same car, what went first

Happy to be told this is normal. I would just rather hear it from someone who owns one.