It seems the multitrack edition feature in Melodyne 4 Studio is no longer working in CbB. Multiple instances of the plugin aren't talking to each other, so each instance is only showing one track instead of all of them. It isn't Melodyne itself because it works as expected in Studio One.
 
Is anyone else experiencing the same thing?

It's still working for me.  I'm working on a song that I have two tracks using Melodyne.
However, in order for me to work with multiple tracks, I have to shut down Cakewalk after adding a second Melodyne track, in order to work on multitrack features.   This (for me) is nothing new.  I've always had to shut down and restart Cakewalk / Sonar to get the multitracks of Melodyne to work together.

See my next post for a screenshot taken today.   I don't even need to shut down Cakewalk, I just have to close the project and reopen it for the multitracks to be displayed. And these are TRACK fX, applied to the entire track, NOT a region FX. (that might make a difference)?

Screenshot from just a few minutes ago using CbB and Melodyne 4 (4.1.1.011) latest version 64-bit -VST3.
Note the two audio tracks of vocals.

Hmm, interesting. I've never had to shut down the software before Melodyne would recognize the multiple instances/tracks, but I'll give that a whirl.
 
Thanks!

Melodyne Studio has been working fine for me as well.

Well closing/re-opening CbB did the trick; Melodyne now shows multiple tracks in a single instance. I wish I could pinpoint when it stopped working as expected, but my best guess is that it happened after the transition to CbB.
 
Strange that it works as expected for some and not for others, but at least there's a workaround. 
 
Thanks for the help.

I had this issue within platinum and started emailing with Melodyne help, and it continued into CbB and I continued to email with Melodyne help. I couldnt get multiple instances used as track plug ins to show up in 1 Melodyne window together, each Melodyne instance would show only what I had transferred into that track. If I used Melodyne as region fx instead, all tracks would show up in 1 melodyne window. I never got it figured out with Melodyne help, and they couldnt recreate it in platinum or CbB, so I just began to use it on multiple tracks only as a region FX. I will try this suggestion to see what happens next time Im using Melodyne on a few tracks.