Attendance and Participation

I am a first semester graduate student attending a prestigious (in name) university. Most of my professors are amazing and I have had no problem with their grading. However, one professor I have (without providing any feedback) gave me a C for attendance and participation when I attended every class. Other students in my class who had missed multiple classes received As or Bs in attendance and participation.

After I reached out for more feedback, my professor says they did not hear from me often enough but I honestly don’t think they learned most people in the class’s names. Additionally, I did speak a good amount and participated in every in person and online group activity.

I received As on all of my major assignments, but because attendance and participation was 16% of the course, the C gave me an A- as my final grade.

I’m worried after speaking to everyone else (many of whom spoke just as much or less as me) who received high marks that this grading process may not be fair.

Because I received zero feedback, there was no rubric utilized, and “participation” is so subjective, is it worth it/justified to escalate this to my advisor to gain more clarity on how to improve in the future and learn what I did wrong or will I just seem like difficult or like a grade grubber?