Blue Cave, slow ethernet speed while in AP mode

Hi!

I have a main router RT-AC1900P.
If my PC is connected to it, I have a full 1000Mbps speed to my NAS.

I bought a Blue Cave to use it in AP mode to extend my WiFi in the house.

BEFORE
NAS -----ethernet------ RT-AC1900P -----ethernet----- PC = 1000Mbps

NOW
NAS ------ethernet----- RT-AC1900P ------ethernet------ Blue Cave (AP mode) ------ethernet------ PC = approx 200 Mbps

I tried to put the Blue Cave in Router mode but with DHCP deactivated and it worked. The issue was that the Blue...

Blue Cave, slow ethernet speed while in AP mode