The time to print a file will vary. The biggest variable is the time it takes to heat the nozzle and/or the bed. There may be other commands in the beginning of the file that take a variable amount of time to complete.
It looks like less than 10% difference in the two times based on your screenshot.
Thanks for your answer ! It took few minutes more than indicated at the right but that meant more than a 15m difference which is not normal, as in it never happen until now, the "last print time" is usually quite precise and consistent, with only a variation of seconds. This is mostly a question of what could possibly cause that in your opinion (nozzle and bed heat before print, as I start them both at the same time before starting the print)