Have you tried using the “correct distance” feature? Sometimes my Garmin will lose connectivity with the satellites or something. I’ll note that it is still displaying my speed but the distance is not changing. When this happens, and I happen to notice, I will turn it off and back on. That generally fixes it. Then I will use the “correct distance” feature in Strava, which usually corrects the mileage after the fact.
For my own personal reference, if I forget to start my Garmin or other bonehead move, I will add a private manual ride to my feed so that my overall mileage is relatively accurate. This, of course, will not count towards Freezing Saddles.
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