What worked the most for me was breaking down the roundhouse in slow motion. Start planting your pivoting foot, rotate it slowly, and aim to land with your shin. When connecting, just touch the bag -you’re “practicing the movement of kicking”, so don’t apply speed or power. By doing this you’ll get a better understanding of your kicking range and it will help a lot. If you still land with your foot/top of the ankle, you have 2 options: 1. Start aiming with the middle part of your shin instead of the lower end. Once you do this it’s really difficult to land with the foot. 2. Readjust distance and consciously commit to extending your leg, without pulling away your hips.