Cortex & controller not detecting keys

Hello, our cortex is not connecting to our controller. The robot works fine when directly tethered, but not when using the keys, We’ve updated the firmware for the cortex, keys and controller and still they are unable to connect.
After a few seconds, on the cortex the VEXNet LED blinks red.
Any help would be much appreciated.

Hello fent1,

We’re sorry for the delayed response.

Have you checked the make sure the VEXnet 2.0 key is firmly connected to the Cortex? It’s possible that the USB has become loose in either the Cortex or the key, and this can result in poor connection. After the Cortex VEXnet light has begun blinking red, you must restart the Cortex before it will begin searching for VEXnet again.

Is your VEXnet 2.0 key free from any surrounding metal? If there is a large amount of metal surrounding the key, this can severely impact its ability to connect. If your design requires your Cortex be buried deep inside your robot, a USB extension cable can be used to move the key into open space.

Have you tried swapping your VEXnet 2.0 keys for a different set? It’s rare, but keys will occasionally not respond and need to be replaced.

Hope this helps.