Fenix 5 gps accuracy

Hi,

I completed a 5k parkrun using a Fenix 5. The run was 3 laps in a woodlands area. Anyway after examining my results I found my run was short by 0.2km and the gps trace was all over the place. I then compared my results with other runners and they had better and more accurate results. I must be doing something badly wrong or my watch has become defective? I had gps set to gps + glasnost and smart data recording. Both 3Ds were switched off

my results


Apple Watch 4 runner


garmin Fenix 5S runner

Thanks in advance for any help and guidance