is there any custom rom for j7 max
Or what u can do is when asked about whether ur device is rooted or not click on I'm not sure now greenify will launch.then go to settings change working mode as root.Its done
I had the same issue.Just check ifvypuvhave a SuperSU update and try again.
U see the 'next' tag on greenify on your pic,click on it as soon as greenify go checking for root access just don't wait for the result.
Try it,worked for me.thank u