We have a modem from the internet provider that has Wi-Fi built in, but it is not enough for the house, so I have a router in my room to get some Wi-Fi here too. My problem is if I connect directly to the modem by cable I have full 300mbs speed, but as soon as my router gets in the picture, it is limited to 100mbs. My router is an asus rt-ac1200g+.