I was denied to board at the LAX arriving 40 min before departure time because I should be there 45 minutes instead. So I was basically 5 min late and the airport wasn’t busy at all, not even 1 person is waiting at the check-in line. I later found out from another agent at the evening that she could have tried to call the gate for us and believed there would still be enough time in my situation. Instead, I was just handed a boarding pass from the afternoon agent and told that my flight is 6.5 hours later and she didn’t say anything else or explain anything to me. And the evening agent told me that lucky that I stop by the counter first because he didn’t even see us on standby for the next flight and also explain to me that I had an option to pay $25 to guarantee a seat, so I went for it.

I'm not totally just blaming on her but I just thought she could have provide a better customer service or put more effort to help.