Vexnet keys lose connection

My vexnet keys (new white ones) lose connection as soon as we start the motors with the joystick. I have made sure that we have used utility upgrade 4.1.5, both cortex and joystick are running 4.23 firmware version, and keys are V1.46. I have even reconfigured cortex and joystick. We have also tried RobotC V4.27.
This happens at different buildings within our district. Our cortex’s are of varying age from 5 years old to new last year.
Someone at a different building with all new equipment last year is having no problems. Not sure if that has anything to do with it all, but seems strange.

Does anyone have any idea why this happens?

Hello mpfafftaylor,

It could be that there is interference affecting your VEXnet link.
Have you tried running one of your systems outside of your building or at home? Do the problem persists even if you are in tether mode?

Please confirm.