2015 Peguet 508 Slight Strike in Strips

Until 2 weeks ago, I sold my Opel insignia and bought a 2015 Peguet 508 Bluhdi Allure model car.

I am satisfied with the overall characteristics of the vehicle, but I feel that it is skidded at the rear of the vehicle.

Even this slight skid is felt when changing lanes. In the pits, the vehicle shakes like a swing.

However, I need to constantly check the steering wheel of the vehicle. Because even in rough areas on the road, I feel as if the vehicle will slide and be thrown slightly to the left and right.

I have never used a Peguet brand vehicle before, so I couldn't make sense of it.

I am curious about your experiences on the subject and whether you have encountered a similar situation before.

Thank you, conveniences.