Corning kit terminations

I need to make terminations but my termination device won't stop blinking and my connector is moving around in it's slot after I close the device. Got two to work before this but i've had no luck since. Is anyone able to assist with this?

I need to make terminations but my termination device won't stop blinking and my connector is moving around in it's slot after I close the device. Got two to work before this but i've had no luck since. Is anyone able to assist with this?