I have 2 decos connected through cable creating the mesh of my wifi network, the first time that I configured the 2 decos and tested my connection speed it was near the contracted speed of my ISP (600 Mpbs), but there is some time now that I've been noticing that my connection does not pass the 300 Mbps. I didn't change any configuration in my routers, but when trying to get the full speed I did some tests and discover the following.

The QoS is enabled and set to 1000/1000 for both tests:

1. When configuring the PPPoE the internet connection stays limited to 85 Mpbs (only on wifi)
2. When connection through dinamic IP (ISP router as a modem connected in the deco through cable) the connections stays limited in 300/300 Mpps (Donwload/Upload), If I use onlye the ISP Router the connection stays fixed at 600/300 Mbps.

I've tested the Deco as a Router and AP mode, but in both cases the internet is still being limited at 300/300.

I don't know what to do anymore to solve it.

I already tested all the infrastructure and came to conclusion that the problem is withing the Deco.