MCM5 vibration at fixed speed

[Pingouin]

Hello guys,

I need your experts diagnostic ! I'm using a gotway MCM5 that has a very high frequency vibration (felt mostly in my feets) occuring at about 10-12kph (6.2 to 7.5mph) that dissapears above and under, it seems to be mostly at constitant speed and not during deceleration phases. This vibration is not present if I just lift up the EUC and make it free spin at these speeds.
It is not unrideable but not very pleasant and makes me avoid this range of speed.
Do you think it's just the motor that has this "resonance" speed or can it be something else ? I saw @Duf mentionning something that could be similar with his 16X but I'm not sure it's the same here.

Thanks all for your precious help !

[houseofjob]

Have you gone through the usual suspects for vibration?

1. Check for a loose axle nut (use threadlocker if it keeps unscrewing)
2. Check for a broken axle
3. Check for loose pedal arm/column screws that secure to the inner shell (use threadlocker and/or locking washers if it keeps unscrewing)
4. Check for a loose control board (insert pieces of rubber (like pieces of a rubber band) inbetween the board and the shell to dampen/vibration isolate from the shell)
5. Re-calibrate the wheel/gyro with the wheel completely vertical/upright, not leaning at an angle.