Draytek Vigor 2925ac - Were is the Bottleneck?

Hello.

I have a Hytron router provided by the ISP.
It provides a 200Mbps broadband if tested by ethernet.

I connected to it, in bridge mode, a Draytek 2925ac.
Testing the internet speed on the Draytek by ethernet shows a 45% slower result.

I guess I have no setup on the Draytek that can cause this. Either QoS or data flow monitor are off.

Any clue?

Thanks.