While travelling downhill at speed Level S, a chassis error appears and the vehicle stops.
Using a lower speed level significantly reduces heat generation and usually prevents drive protection from activating.
This is intentional drive over-temperature protection. When the battery is nearly full, braking energy generated downhill cannot be fully stored in the battery, so excess energy is released as heat. On a long or steep descent at higher speed, the drive system can reach its thermal limit and temporarily stop to prevent long-term damage. This protection is not related to a software update.