FR 945 speed, power, cadence disapear/reapear randomly during indoor cycling (magene T300)

Hi everyone, 

I have some bad experience when doing indoor cycling with magene T300 and FR945. I dont know which gadget is abnormal.

During workout both or some speed, cadence, power data dissapear / reapear randomly or power is not same during ERG mode. 

Kindly to help.