This may help.
I have a similar problem here, except I'm using 48KHz. Cakewalk converts my 16bit 48KHz mono audio clips into 32bit 48KHz stereo clips when they're bounced and the Sample Rate Conversion message comes up because of this.
Windows File Manager confirms that the source clip files (recorded by Cakewalk) are 768kbps, whereas the bounced clip file is 3072kbps. VLC Player confirms that these files are 16bit mono and 32bit stereo (16x48KHz = 768kbps and 2x32x48KHz = 3072kbps) respectively.
While it makes perfect sense to convert source clips to a higher bit depth internally for processing within the programme, I'm not sure that this message is needed if the input and export bit rates remain the same (in my case 16 bits).
(Windows 10 and my interface, Cakewalk driver settings, project and template settings are all 48KHz. )
