Overlapping Copy-Paste creates zombie clips (bug since X3)

Choose two audio clips of similar length with a visually distinct attack and decay. Two piano notes are ideal.
Create a new project with one single audio track.
Turn on Options > Auto Crossfade.
Put the two clips into the audio track with about twice a clip distance between them.
Select the first clip and press Ctrl+C to copy.
Position the mouse on the timeline above the middle of the second clip and click to position the cursor there.
Press Ctrl+V to paste.
 
Now try separate the two clips.
Try by moving the exposed part of the leftmost clip to the left.
Try by moving the exposed part of the rightmost clip to the right.
For fun, straighten out the crossfade, then click on various parts of the clip.
Sometimes just moving the mouse over the clip causes strange effects.
 
I am trying to put together a guitar track from separate guitar samples and this is driving me nuts.
 
This problem was introduced in X3.
X2 keeps the clips separate.

I'm guessing you have Drag and Drop mode set to 'Slide Over to Make Room' in Preferences > Customization > Editing? That setting has had issues going back before X3. I can't replicate anything like what you describe with 'Blend' mode selected, which is what you would want for crossfading overlapped clips.

I have seen the issue with crossfades breaking off as separate clips when moving clips in lanes with crossfades created automatically by the comping tool, but have not seen it with crossfades created by overlapping clips in a single-take parent track with lanes not showing. I gather that was the issue you mentioned in your other thread that seems to have been addressed by 17.02 Early Access release.
 
http://forum.cakewalk.com/FindPost/3561585
 
Not sure where that leaves this one.