at the place I bought it from, they put their sulcata in a terrarium with the right humidity. and I soak it every dayNot fungus. I would keep an eye on it, but not do anything yet. Is your tortoise being kept in the correct warm humid conditions? Was it housed too dry before you got it?
What do you consider the right humidity? What percent? Most people consider the right humidity much too low.at the place I bought it from, they put their sulcata in a terrarium with the right humidity. and I soak it every day