Incorrect swing speed

Morning all,

I’ve had my g80 for a few months and I’m not massively impressed. Having quite a lot of small issues but things I can overlook. One issue I’m having that I can overlook is massively wrong club head speed measurements. For instance yesterday I was carrying a 5 iron 180yds, all other measurements (tempo, carry etc) seem accurate but the club head speed is showing up at 30mph which is obviously miles off. I’ve carried out the latest software update and reset the device and it still not working. Any help would be much appreciated.

cheers Golfer‍♀️