Garmin fenix 5 not recording 1st part of run activity.

Hi, for the past month, when I am doing a running activity, the fist 1km of my run isn't being recorded, even though I have waited for the GPS signal on my Fenix 5 watch to go green before I start my run. It records the overall distance correctly, but on the GPS map it shows that I started my run 1km after I actually started?!

It is recording my cycling activities correctly it seems to just be my runs?

Any help would be much appreciated 

Thanks Ok hand

Laurie