Two different flight, two different drones.
I’ve done stuff with my M2P and got a relative accuracy of 1 to 3 cm and with the company’s P4RTK and got 4 to 8 cm accuracy.
I had the the same GSD of 1 cm and the same overlap of 80/75.
The only difference I know of is that the P4RTK has a bit wider lens than the M2P and the P4RTK has a mechanical shutter.
How does WebODM compute the accuracy? Can this just be a mathematical difference?