Reboot the device.

Check physical link speed between device and the first piece of infrastructure.

Check physical link speed of all links between the client device and the rXg.

Make sure that both ends match.

Inspect the cables. Ensure the cables are in good shape and free of damage. Ensure that the cable heads are properly seated. 

Ensure client device is running latest software. With desktop computers check for BIOS updates.

Try to replicate the problem using one of our devices running through the stack of equipment delivering Internet to their room.