I think it's not a sensor issue, because if it was the problem would appear when the car is started (so the sensor is activated).

I think it's a mechanical problem on the suspension arm, that the sensor detects and corrects when the car is started.

I think what you have is a mechanical, conventional suspension, with a weight-sensor that can change the softness of the suspension in relation to the weight in the car. It's not a pneumatic suspension from what I know. So for me it's probably an oil-leaking damper, or something like that, but I'm not an engineer.

You should look at your suspension damper to see if one is not oily or very very dirty compared to the others. It's showing a dead damper.