In his 2019 review Court said the radrunner had a geared hub motor. This should not drag unpowered.
OTOH it has 20" x 3.3" tires. Fat tires are known to drag quite a bit without power. Have you ever ridden an unpowered fat tire bike before? I haven't. Since I ride unpowered about 80% of the distance, I made sure not to buy a fat tire bike. My 2.1" tires will air up to 55 PSI. I read that fat tires are not rated for that much air pressure.