AI parameters wrong. Like they are trying to finish the game instead of wining it.
Last night a player left and AI replace him. just before the game end i had a road building card 9 pts and 3 cards. The other player had 12 pts 4 progress cards and 10 cards. AI played and he used a spy card against me and moved the robber and stole me. the 12 pts guy had 5 roads, I had 6 and AI had 2. then he tried to take the road using the card and then he try the trades to get another 3 roads. the other player then simply made 2 roads and the game finished. if a real player was playing he would use the spy against the 12 pts player and use the robber against him as well.