This happens quite often, Calilasseia. Sometimes there are two or more common words in a game, sometimes (as in today's challenge game) one of the words is common and one of the words is uncommon. There was one game a few weeks ago which had three common 9-letter words.
One way to check how many 'big' words there are is to look at the 'all words' scoreboard and see how many stars there are next to the names of the players who have cups.
MK