I'm not familiar with that Yamaha chainwheel drive crank unit and Gepida only list Bosch new generation crank units on the current Alboin models.
The problem is most likely a bicycle one rather than related to the power unit, but check the lateral stability of the chainwheel, it shouldn't have a large degree of lateral slack although some on this type of unit is common.
On the bike side common causes are a tight chainlink rivet not allowing free rotation, the derailleur rear mechanism not pivoting freely or having too slack a tension spring. Also check the rear wheel is free to spin forward without dragging the chain forward as it does.
It's unlikely to be a serious problem, perhaps just something out of initial adjustment or a pre-delivery check item missed.
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