Stop sensor
Stopping a sensor in xDrip+ has very different functions depending on the sensor itself.
G5, G6, ONE and G7⌁
Reference documentation is here.
Libre⌁
xDrip+ is not able to stop a Libre sensor, actually you can't stop this sensor: if it doesn't fail it will run it's useful lifetime and stop by itself after 14 days and 12 hours.
xDrip+ sensor stop is only used to invalidate previous calibrations. This operation is necessary and recommended each time you replace your sensor.
Confirm STOP SENSOR unless you only want to reset all calibrations.
Confirm you want to stop the sensor.
If you change your mind and the sensor didn't expire yet, you can always "restart" it, il will resume the current session and eventually ask for a new calibration. xDrip+ doesn't physically restart Libre sensors.
Followers and companion apps⌁
There is no interest in stopping a sensor when using a follower app.
Warning
The only exception is xDrip+ Sync follower that might transmit the Start or Stop command to the actual sensor if it is directly connected to xDrip+ acting as master.
Do not use Start and Stop sensor with xDrip+ Sync follower unless you know the person with the master xDrip+ phone will know what to do with a stopped sensor!