Trading bug (not common)
Yesterday had a weird bug for the first time:
During my turn I waned to trade 2 ore for grain (really does not matter for what). No trade was accepted, I left the window and ended up turn.
Next turn I had to trade 2 wood for grain (had a port) but trade window still showed that I want to trade 2 wood + 2 ORE for grain. I couldn't unswitch the ore so went for it - thought will be a bug.
Bud ended up losing 4 cards for one grain in the end.
So far it happened just once with me and never again in that same game but it was still quite unpleasant surprise...