I track all my runs on my Garmin Forerunner 645 watch. It's nearly perfect, but occasionally it does fail me and today was one of those days.
I set out for my run as usual this morning. The Garmin locked onto the GPS signals, found my RD Pod and heart rate. I pressed go and off I went. Usually about 400m in to the run, I'll take a quick look at my watch to make sure it's tracking. That was all good today and so I continued, thinking about how far to run on this freezing cold morning.
At 1km, I got my first lap read out through my headphones and that confirmed things were working as planned. But at about the 4.5km point, I realized I hadn't heard a lap callout in a while so I checked the watch quickly.
It was stuck on the lap time with two options: Save or Resume. I resumed the run and it worked fine through to the finish. I figured it would be about 3.5km missed...oh well.
Garmin's Connect website is great because you can manually adjust the distance and time on a run to account for instances like this. Strava is not. They don't allow you to edit anything about the run which is a feature many users have been asking about for years.
The only option left on Strava is to create a manual entry to add the distance and to set it to private to avoid having it show up in your feed, but still clean up your total distance for things like the weekly and annual goals. That distance is not included in challenges.