An interesting (and annoying) problem I ran into last month whilst travelling on ET through an SQ award ticket.

When I got to check-in, I asked if there are any free exit row seats I could move into. Agent said there were, but then could not move me into one as I was "too young". Turns out I had MSTR as my prefix, rather than MR - even though I am 19. The system wouldn't let them select the seat, so I had to stay in my original assigned seat. My KF account correctly has MR - which I had to call to change from MSTR many months before booking this ticket.

A few questions from this:
1. How was the SQ agent able to put me on a child's ticket, given they had my birthday? (I called to book the flight)
2. Could having a child ticket possibly lead to me not being allowed on a flight?
3. Is it more likely that the SQ customer service agent messed up my prefix, or could SQ have it incorrectly listed somewhere in their systems still? I suspect the former, as other award tickets have correctly had MR.