Issue getting answers to display correctly using Latex and Fill in the Blank

Hi, I'm trying to use Fill in the Blank to create some matrix multiplication questions for students to practice with. I'm using Latex to create the matrices and it runs fine, except when I add the * * to denote a space when student's are supposed to fill in the blank. I have included pictures of my inputs and outputs. Does anyone know how to get around this issue, or is there a different question type I should be using instead to get the output I'm looking for? Thanks in advance for your help!