I honestly don't think they know what talking about, im on Virgin contact, have been for a good few yrs, always got delivery reports, I got this s21 5g in April, still I was getting them up until a few a weeks ago so I went checked the settings etc, they were on, ive had Samsung fones since the first push up pic fone came out (showing my age now lol), im no expert by no means, but I am pretty good knowing my way around them, but I tried everything, the only thing I didn't do was factory reset, when I finally got on to a human they were telling me to do what I'd already done, tryn to tell them this was practically impossible, then be told an answer to an issue I never even had or mentioned, honest to god, waste of time, if I was you I'd ring that number I gave u, u will have more chance of getting the issue getting sorted. Good luck 👍 don't forget let me kno if u get sorted, im debating whether to put all my onto laptop & do factory reset, its just so much messing.