I have been having trouble with the Dexcom G6 staying on me for the full ten days.
A lot of us have been having this issue, according to Dr Google ;)
I have figured out the overlay tape doesn't last the full 10 days either. So I have been putting the sensor on, then just about when the tape starts coming up, add overlay tape.
I have even had to trim the overlay and put a second layer on it, but that usually does the trick. I think we can get overlay tape free from Dexcom, as they did send me one packet, but I have bee using a tape on bought on Amazon and leaving the Dexcom for emergencies. It's in my bag in case I have an issue when I'm out and about.