When I have three expeditions to assign a team to and they are all too difficult, I generally reshuffle.  I have noticed today when I do this all three tiles are exactly the same.  This has occurred at least six times in a row.  The odds of this happening in six random shuffles seem highly unlikely.

Now that you say it I have been getting a lot of identical expeditions at the same time lately, got it again just now but that was from all of my expeditions being finished and not from refreshing/reshuffling

Seeing this myself now, also got an error on trying to reroll them. Hmm.