I have just setup a couple of Deco M5 on my home, replacing an Apple Airport network.
I have FO to the house, and a speed of 200/40. The modem was configured with the PPPoE settings there, so the first time I setup the Deco it was with Dynamic IP. Everything worked fine. I could get around 196 mbps down and 40 up.
Then I changed the Modem to be in bridge mode, and setup the PPPoE connection on the Deco. After that change, I can't get anywhere (nor the Deco themselves, nor with a computer connected via ethernet, nor via WiFi) more than 100 mbps down.
Note that the ethernet cable between the modem and the main Deco was not changed at all, and both report a 1Gbps connection as expected.
Just to make sure it was not my ISP, I returned the modem to the default settings, it handling the PPPoE connection, and setup the Deco again to have a Dynamic IP. Now I can get again the 200mbps down.
The only thing different seems to be the device handling the PPPoE connection. I don't expect the Deco to be limited somehow to the speeds it can handle in that case, but it appears to be the case.
Anybody noticing something similar?