Using the entire focus range of your lenses can sometimes prove to be a disadvantage
On longer telephoto lenses and macro optics, where the range of possible focus varies from several centimetres from the camera to many metres, it can take time for the focusing system to readjust the lens elements to the correct positions. This often leads to focus ‘hunting’ and potentially missed or de-focused frames. Try using your lens’ focus limiting switch to restrict lens movement to only a portion of the full track, thereby speeding up autofocus functioning.
When you know your subject will be within the range of feet rather than metres, there is little need to allow the lens to focus all the way to infinity, so select the narrower range until your focal point moves further away.