Come learn 2000+ kanji and 6000+ vocabulary words with WaniKani.
紛れる means "to be diverted." A thing that is diverted goes in another weird direction. It's just a fluke or chance.
One reading does follow the 紛れる reading. But the more common reading is まぐれ. Very similar to まぎれる, but the ぎ goes to ぐ.
It was just a fluke that I was able to answer the questions on the quiz.