Repro:
With touch controls, use your finger to start mining something. Move that same finger around while its held down to mine. You will notice that it moves the camera, if the mine touch button is on the right side. It will move the character if it’s on the left side.
This is not a good user experience because I don’t want to move around when I’m just trying to mine some blocks.
This is how it's always been, and afaik is intended. You press the mine button and can still move the camera off the mine button to continue mining. If you want to stop mining just let go