I got the same at parent's evenings. I was "quiet" in class in that I'd not shout out answers and be continually asking questions, but I did what I was asked, I'd answer questions when directly asked, and I'd ask if there was something I didn't understand, etc. I certainly wasn't "mute" but nor was I "gobby".
But so many teachers at parents evenings would spend the 5 minutes telling my parents I was too quiet and had to speak up more. Time wasted that they could have been spending discussing my actual work, marks, etc.
I'd hoped that teachers would have been more aware of different personalities these days, but we had the same at my son's parents evenings. He went through secondary in the top 5 of virtually every class, never once missed a homework, etc., yet it was the same bloody stupidity at parent's evenings. "Yes, he's doing really well, but ,,,,,,,,,". By this time, I was a lot more bolshy and challenged some of the teachers who said it, I asked them exactly how he could have improved on his 95% in the end of year tests by being louder? When challenged, they couldn't actually answer, and all admitted that he'd always answer questions when asked, and worked well enough in groups etc. I do wonder how he'd have got better than four A*s at A level by being more gobby! He also went on to get a First degree in Maths at a top 10 Uni, and got a really good job at one of the UKs biggest insurance firms, and after just 18 months there, has got a promotion. Funny how his internal appraisals at his Blue Chip employer never complain that he's shy and too quiet!!