UPDATE: With Location Services set to While Using App, I got good tracking for a walk started from the app. BTW, it is not necessary to have the app open and displaying for GPS to work with the WUA setting. I walk with my phone locked in my pocket and tracking works. Unfortunately, a walk started today from the app with Location Services Always On resulted in the usual GPS failure -- sharply straight lines between random points along the route or near the route. Next test will be to change Location Services to While Using App, which did work before for an app-started walk. Before this issue, I always left it on Always On, if only because the app will hound you to change it to Always On if you don't have it that way, suggesting that the app won't work without it Always On.
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