Error in the rhythm the clock is marking.

I've noticed in my last few runs that when I'm running and my pace isn't as it shows on the watch during the run, when I go to look at the app, it appears as if I'm standing still and when you look at the map you see that I was running. I've already changed the GPS, but it still didn't have any effect. Here are the runs that show up these days.

https://connect.garmin.com/modern/activity/18407253697
https://connect.garmin.com/modern/activity/18440061331
https://connect.garmin.com/modern/activity/18453202875

It's like I was idle on these runs but that didn't happen. I'm suspecting a GPS glitch.