Cakewalk is working as designed.  Just set the channel on your controller and you will be all set.
 
The only problem I can see is not fully understanding how MIDI works. 

abacab
Cakewalk is working as designed.  Just set the channel on your controller and you will be all set.
 
The only problem I can see is not fully understanding how MIDI works. 

In the many years I have been using Midi, Sonar, and Native Instruments, I have never had to set the channel on my controller to have things work as they should.
 
But I would be willing to try it. How do you set the channel on a controller and which channel would you use?

Not sure what else that I can add that may help.  I have been using Cakewalk for 20 years, beginning with external hardware MIDI synthesizers and sound modules communicating over MIDI.
 
I don't see any recent changes in Cakewalk in regard to how MIDI has worked for years.  You will need to consult the user guide for your MIDI controller to understand the specific MIDI channel settings and options for your unit.
 
I will mention again that some DAWs do not re-map the MIDI channel at the track input settings, and some do.
 
Multitimbral plugins like Kontakt will look for MIDI data on specific channels, if the instrument slots are set to anything other than "Omni".  So setting the MIDI channel in the Cakewalk track will not alter the channel that your controller is sending the MIDI data on.
 
See the free utility MIDI-OX if you want to monitor the MIDI data sent by your controller.  It will show the actual MIDI channel that the data is sent on.  http://www.midiox.com/

abacab
Not sure what else that I can add that may help.  I have been using Cakewalk for 20 years, beginning with external hardware MIDI synthesizers and sound modules communicating over MIDI.
 
I don't see any recent changes in Cakewalk in regard to how MIDI has worked for years.  You will need to consult the user guide for your MIDI controller to understand the specific MIDI channel settings and options for your unit.
 
I will mention again that some DAWs do not re-map the MIDI channel at the track input settings, and some do.
 
Multitimbral plugins like Kontakt will look for MIDI data on specific channels, if the instrument slots are set to anything other than "Omni".  So setting the MIDI channel in the Cakewalk track will not alter the channel that your controller is sending the MIDI data on.
 
See the free utility MIDI-OX if you want to monitor the MIDI data sent by your controller.  It will show the actual MIDI channel that the data is sent on.  http://www.midiox.com/

Thanks for you reply.

Install the full Komplete 11 package and all the latest updates. Verify with VST Manager you are using the same Kontakt.dll as Studio 1 and Standalone.

After reading the OP again, my best guess is that the MIDI controller somehow got switched from MIDI channel 1 to something else.
 
This wouldn't be obvious if you were using the DAW or an instrument in Omni mode, but any other setting would result in this issue.
 
It would only take a few minutes to confirm with MIDI-OX which channel your controller is set to transmit on.
 
And if you posted the specs of your keyboard controller, maybe someone with the same model could assist with checking the settings.