Looking at the
Results,
it looks like two of the drivers (Thiago Camargo and Eder Penetra) either had issues on the start or started from the back, and then pit early. They were behind you, but probably turning faster laps which means when you pit, they had made up enough ground to overtake you. Thiago fell off the lap after you pit in, so you gained that spot back.
Nick Ireland was behind you, but pit two laps before you. Again, he probably had little traffic, or just enough pace, that when you made your stop, he leap-frogged you and one or two others.
You ran a 2:04.499 in-lap, and a 2:36.093 out-lap with a fast lap of 1:55.739 and a race average of 1:58.739. Nick had a 2:00.527 in-lap and a 2:27.429 out-lap with a fast lap of 1:55.894 and a race average 1:58.308.
Your pace was really close, but he beat you by nearly 4 seconds on the in-lap and another 8.5 seconds on the out-lap. I don't know whether you were contending with traffic on your in-lap, or just had a slower, more conservative, entry to pit-road? On your exit, did you pull off with traction control? Did you have any traffic at pit-out?
I would double check that you took the right fuel, because 12.5 seconds is a lot to lose. Maybe you were slow in, but that 8.5 seconds out really cost you. Your other lap times don't show there being enough pace difference to result in the loss unless you were held up in traffic. You were even faster than Eder, but his in-lap was a 2:04.043 (same as you) but his out-lap was a 2:22.197 (14 seconds FASTER than you!!).