Kulula HLA to DBN... problems

Hassles with kulula on the HLA to DBN route. Recently kulula flights have always experienced delays. On the 13 October 2018 flight at 10.20am from HLA to DBN. We checked in online the night before (no checked in luggage, only hand luggage on hand). Got to the departure gate at 10am and they refused to allow passenger in saying that we are late. However they rescheduled the flight for 17.30pm the same day without any additional charge. On 03 November 2018 flight from HLA to DBN 17:30pm delayed by 20 minutes, no notification was sent at all, get to the boarding gates at 16.30pm only to be told the flight is delayed by 20 minutes. It's a bit weird how kulula refuse to allow passengers 20 min before a flight but offer to reschedule the flight without any cost. Also, it's online check-in platform is quite slow... boarding passes either don't get emailed to us, or it's emailed the morning after we check in online. I wonder if it's a network or website issue. Used to enjoy flying kulula because they were always on time. However, recently started having issues... twice in one month. Disappointing.