Right pedal stops showing smoothness after a few seconds

for some reason, my right pedal on my Vector 3 dual power set up only shows pedal smoothness for the first 3-4 seconds when I start pedaling, then it goes blank. it shows power and balance though. 

it also disconnects whenever I stop pedaling and get " rigor pedal missing" , then reconnect when I start again, shows smoothness for 3-4 secs and out again.