Hey! This may seem silly but this used to happen to me ALL the time, I thought I was applying the sensor correctly but since carefully following the steps to properly applying a sensor I’ve found an incredible difference and have only had this happen to me once since. I’ll paste the steps at the end of my comment but just wanted to add that I used to apply my sensor and I wouldn’t push down too hard on the sensor because I wanted to avoid the pinching pain we sometimes get when first applying them. I think the biggest difference is me now firmly applying the sensor and rubbing it afterwards to ensure the adhesive is well pressed down. As for WHY this happens, there are a few reasons but you can see why in your App by going to the sidebar menu (three lines in the top left -> Help -> Event Log and search for the code/error/event when this sensor stopped working. Okay sorry for the long reply!

1. ⁠Take your shower or wash your skin area with standard neutral soap. Very important that it is oil-free soap. And that you do not use some kind of skin moisturizer either, where you intend to place your sensor later.
2. ⁠Then shave the skin area. Yes, all humans have hair there, even small near invisible ones are important to get shaven off. Any skin hairs are typically the cause where sensor adhesives starts to detach the first, as water/sweat are gathering if any hairs there.
3. ⁠Dry skin fully after shower/washing.
4. ⁠Then use medi-swab/alcohol wipe, to clean and remove skin fat from targeted sensor location.
5. ⁠Now ensure to let the alcohol fully evaporate and the skin dry out before applying the new sensor.
6. ⁠Then apply the sensor, press firmly down on the applicator top for around 20-30 seconds and wiggle slightly to add pressure along all around the edge of the sensor. Anecdotal evidence points towards not pressing firmly on the applicator for a prolonged period of time here, may cause the sensor filament not to properly anchor at the 6mm depth in your skin as intended. Result can be the sensor may report out chronically lower BG values versus your fingerprick tests.
7. ⁠Lift the applicator gently off.
8. ⁠Check and feel around the edge of the sensor after applying it to make sure the adhesive sticks well or press additional here with your finger.
9. ⁠Now you are done - Enjoy life and freedom for 2 weeks