I can feel your frustration re diet and exercise as the lowest I've ever knowingly been is 39 despite a low carb diet and lots of exercise (running, walking and gym). In the first lockdown I took the opportunity of having total control of everything I ate and lost half a stone fairly easily (low carb) but my Hba1c was still 40. As HSSS said, I think we all have preset levels related to our genetics, and pehaps this is the lowest I can go. I also have Hashimoto's which may play a part. It's annoying as a friend of mine who eats a lot more sugar than I do, is a bit older and who does less exercise than me, had a recent result of 34!