This is expected behavior(at least has been here for as long as I remember). To shorten or lengthen a fade, use the [ tool to edit the length. This is changing a fade, not deleting a portion of an existing fade. Selecting the clip with the entire fade and hitting delete is supposed to remove the fade. Sometimes, deleting a fade and re-doing it is the fastest method(I have done both methods and can't say I have a preference). Not sure if I explained that well, but hopefully I did