Hi,after updating firmware I tried 5 minutes in my garden, in the dark... The drone was not very stable, is due to low light? Maybe sensors have problems in the dark...

The drone was not very stable, is due to low light?

Yes. VPS is what provides much of the stabilization you normally see when the Mavic is hovering, but if it's too far above the ground, if the lighting is poor, or if there's no "pattern" the downward sensor can use as a reference point the Mavic will drift around a bit as you described.

Thankyou

Yes, it may be caused by the low light, please try to test it in the daytime , I would also recommend you calibrate the IMU.