Retro Gaming<br>Clint loved playing classic games from the 1980s. His dream was to own an original Pac-Man arcade cabinet. His family built him a replica for his birthday. Clint loved it and thanked his family profusely. Inside Clint felt a pang of ingratitude at it being inauthentic.
Clint felt ungrateful for his birthday gift. 
Clint felt ingratitude at his birthday gift being inauthentic therefore he was ungrateful, which is a related term to ingratitude. The two different terms probably confused the system.
( z1 feel :ARG0 ( z2 person :name ( z3 name :op "Clint" ) ) :ARG1 ( z4 appreciate :polarity - :ARG0 z2 :ARG1 ( z5 gift :mod ( z6 birthday ) :poss z2 ) ) )