We've had some instances of unexplained data loss from repeat sections of two different forms. We're running Survey123 on iPhone 5c, and are usually in airplane mode while in the field to extend battery life. The data losses have occurred while we are entering repeat records every few to several minutes apart, sometimes turning off the iPhone screen to save battery life, sometimes it goes to sleep on its own. For example, the other day we were entering weights and measures of newts in our Apex form. We had entered 11 repeat records and went into Survey123 to enter another repeat and only the first 7 records were there.
It has also happened with the repeats of another form (see below).
It doesn't seem to be gross user error, and I can't figure out what in the forms' structures would cause this to happen infrequently. Any helpful advice appreciated!