I've not experienced the issue. But if I had, I'd probably be initially looking at eliminating the following:
- Checking the props to make sure they're not damaged.
- Checking the props are fitting snuggly without the wobble/rattle that was reported when the I2 was originally released. Shim them or replace them if they are really loose.
- Checking the prop mounts are not loose on the motor and that there are no cracks in them.
- Checking the motors are not lose on their mounts.
- Checking the alignment of the motors - see if the ends of the props are in line with the neighbouring props and aren't twisted out of line.
- Checking the VPS sensors are clean and clear and recalibrating the VPS system.
Did you update the firmware before the issue started? if so, see if you can roll back and then recalibrate everything.