Hello. I'm printing on K1SE with creality hyper pla. After at least 15 perfect prints (around 120h) there is a layer shift on normal speed. It is OK when I reduce speed to 50 % but I struggle to fix the problem. I have checked x and y belt tension. I have tried to reduce acceleration and travel speed to 5000 on creality print slicer and there is again bad prints. I'm looking for advice. Do I need to check z belt (and how)? Do I need to change slicer? Which parameter/profile do you recommandé to me ? I don't know why but 50% speed option give me only 33% more of printing time. I can continue with that option but I'd like to understand...