Welcome!
One other caution on interpreting test scores is that this is probably the MAP 2-5 rather than the 6+, so it doesn't actually have 8th grade skills on it (might not even have 7th), let alone 11th grade content or skills on it. Percentiles are more meaningful than grade equivalents, in this case (and many other cases).
The confounding of rapid work completion and high conceptual aptitude is, unfortunately, pervasive in GT programs.
And based on Kai's norm-checking, it looks like your DC is probably still under placed by about a grade in instructional level.
