It used to be easy. Click the clip, click "fade out (or in) audio" and it happened. The fade points could be adjusted to give a longer fade if I wanted one. Now, I can't shift the things and in any case the fade doesn't go to zero, or in other words, silence. This is an infernal pest, as I have to do major juggling of the clips involved to get a smooth transition. I'm re-working the current video in Elements 12. It's slower, but more tractable.
My computer runs an Intel i7 7700 CPU at 4.2GHz. It has 16GB of memory and a 64-bit operating system. It runs on Windows 10. It should eat this stuff for breakfast. Why is there a problem?
Another one, which may be related, is that shifting music from the music track (stereo) to an audio track (5.1 sound) has to be done in at least 2 steps. First, from music to audio 1, then from audio 1 to audio 2 or 3. The same applies in reverse, when transferring files from Project Assets to the various music and audio files, or at least, the ones that involve crossing over the visual tracks, notably video 1. This one is computer-related, as it happens in Elements 12 now. It never happened with my old computer, which was considerably slower and less powerful.
Can you post a screen capture of the clip with the fade applied to this forum?