There are a number of ways to fade IN and OUT.
The f is used only for a fade IN and will be available only on the first clip in the track (or on a clip after a gap).
The X shown above is for transitions between clips and from a final clip for a fade or cross fade. The transitions box that opens when the X is clicked offers many options.
An alternative is to open EFFECTS and scroll to the FADE section there... 
Yes, it can take a different function to fade IN and OUT on a single clip, dependent upon what fade routine is used and the nature of the clip.
Not certain that your vanishing effects are due to the version. But if something doesn't go right immediately press <ctrl-Z> or EDIT menu | UNDO to go back, step-by-step.
Also back up the project routinely using Save Project AS, giving it a unique name or #, so as not to overwrite earlier saves. Save Project will overwrite. That way, you're protected.