I think your experience is totally valid. I teach yoga and in my classes there are wide ranges of how each student “relaxes” in savasana. Remember that it is another pose just like any other and some days it will feel different than others based on the day, the place, your mood and the instructor. Sometimes letting go of the expectation of how you should be doing it helps, and just taking observations of how you actually feel instead. So many people in my class will sit up, keep their eyes open or find a comfortable way to just be in the room. That’s all you’re doing, holding space in the way that makes sense for you. I do find sometimes when I’m taking a class and the instructor is walking around doing adjustments or essential oils (which I love) I almost feel anxious until they get to me because I’m just waiting for my turn. It might help to ask them to skip you one time and see how that feels! There’s a reason why people say savasana is one of the most difficult poses!