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.

I had this happen to me but thought I'd just imagined it - will keep an eye out for it now.

It's happened to me too 

At this point in time this is so clear, that I literally work with it, as long as you finish all expeditions before you check back they seemingly always give you the 3 exact same expeditions although with differing rewards. The only time it differs is potentially if I get back to the expeditions page before all of the expeditions have finished, or they differ too much in finishing time.
This means every time I get an expedition I don't want, I just need to spend 1 reroll for all 3 to be rerolled, and I need less rerolls during the day than before.