Tracking deviation in the checkout process with the standard Google Analytics Module

[spielgigant]

Our store has been online with PrestaShop for 2 months. We use Google Analytics from PrestaShop (v 4.2.2). For the whole optimization on the google side we rely on an external company. We have noticed that the google tracking in the checkout process deviates approx. 30% from the actual figures in the store. According to the external partner, a deviation of up to 10% is normal.

Is this known? Can we do something about it or should we deliberately use a different module? Are there any recommendations?