Just met up with my buddy Rube. He offered to exchange on the first two times as usual. When I declined, the 3rd offer was exactly the same as the second offer. The fourth offer was new but the fifth offer was an exact repeat of the fourth one.
I have had that also, just the last time I saw Rube. Two identical trades offered, one right after the other, so that in all there were only 4 options not 5. I think it must be a recent bug, in the last update.
Also, I wish Rube would go back to trading good stuff for *small* items. When he wants in return your Shovel or even your Orb, you have to replace it and unless you really know the value of every item in your inventory it is hard to figure out if you want that trade.