I usually use Android, but my girlfriend landed me with the above task to solve, and I have found no way to solve it myself.
When we go to Camera Roll and select single or multiple images, we used to get an interface allowing us to select the size of the selected images, including the phrase "Actual Size".
As stated, that interface has disappeared, and all the photos selected are default sent as tiny 130Kb photos. How do I reset the phone to again allow my girlfriend to send Actual Size photos? I have already restarted the phone, but that didn't change anything.