@MARISSASCHRADER this was brought to my attention this morning from a math teacher. Any special character (parentheses, math operators, etc) break the fill in the blank. I've given them a similar workaround, but rather than a similar version of the correct answer, I'm having teachers input nonsense text inside the backticks, something students would never enter as there response. Then, under Text match, they select 'specify correct answers' and input the correct answer as an additional choices, leaving the nonsense text as one of the correct responses.
Unfortunately, this impacts quizzes that had already been made so teachers have to go back and update quizzes so students can take them.