Hello All

Thank you for your replies. I'm sure it was Navel Hard (team of 8 and written in the duty description while waiting for a party).

Fortunately, the problem got solved. I did exit the game and restarted it. Once I did that, I re-opened the duty finder and the Navel (Hard) was showing up as completed, with the green mark! It seems it has been a bug: the duty finder couldn't update timely. Or maybe it was something different, but I failed to see/understand it. I'm just happy it's fixed without redoing a 4th time the Navel again.

Side note: I learned one more thing along this issue. If selecting a trial in the trial section doesn't work, it's most probably because "trials" is selected in the roulettes section. In that case, random choice is mandatory and doesn't let us chose anymore in the other section. Same goes with dungeons.