No data at all

I’ve just bought a G80 and am feeling a bit stupid. I can’t get it to pick up anything at all. I have it on update 4.0. Hitting real balls into a net but nothing. Not even club speed. Also tried the tempo training and again nothing at all. I’ve watched YouTube videos and everything and it literally looks like you switch it on, press the radar button, set it down and swing away. Can anyone offer any help at all? Is there a hard reset I can try?