Great question — answering as the UphillTech team:
See Limited Updates to Background Tracking - "Android 8.0 (API level 26) and higher - Android preserves device battery life by ... If your app is running in the background, it can receive location updates only a few times each hour ". If you want more frequent updates, then you need a Foreground Service .
Full answer by ToolmakerSteve: https://stackoverflow.stackexchange.com/a/68074058 (CC BY-SA 4.0).
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