(1) Advancer doubles, then bids 3♥ promising a 6-card suit (which sounds good to me) but the robot only has a 4-card suit! So I end up having to play 4♥ in a 4-2-fit (4 down) instead of a 7-2 fit in diamonds.
(2) Why doesn't the hand diagram show me playing 4♥? Because after dummy came down, I wasn't fond of playing that hand immediately, and I left BBO. I came back 7 hours later and got the same hand back at an earlier stage of bidding, right after East's 1♠ bid. So I could avoid the trap and insist on my ♦s. Good for me, but I think this shouldn't happen!
(3) Finally I wonder why GIB doesn't let me play 4♦ peacefully (and make it). But since the bidding had been f*cked up earlier, this point is probably not worth discussing.