Maybe a rogue app doing it behind the scenes? Not sure if there is a way to tell what app could possibly be doing it unless there is a feature like there is for wifi that will tell you.
Might want to try a storage cache clear (settings- storage- internal storage- cached data- clear) followed by a cache partition wipe and see if that helps.
How to wipe the cache partition on the Note 8:
Back up data on the internal memory. I've never lost any data from this process, but just in case, back up important stuff.
Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the Android logo displays, release all keys ('Installing system update' will show for about 30 - 60 seconds before showing no command for a few seconds followed by the Android system recovery menu options).
Press the Volume down key several times to highlight 'wipe cache partition'.
Press Power button to select.
Press the Volume down key until 'yes' is highlighted and press the Power button.
When the wipe cache partition is complete, “Reboot system now” will be highlighted.
Press the Power key to restart the device.