Edit: I was having the same issue as you but then I just had to relocate the .dll. Before I had it in the dlc folder so I just cut and pasted it into the root folder and now all of my CDLC works! Hope it works for you too.
Yes, I first downloaded rocksmith 2014 along with the original rocksmith and the transfer packet with cherub rock etc for cdlc on my old PC back in 2016. CDLC works on that pc but I bought a new PC a few days ago and tried doing what I did on that PC to this one but only the dlc from the original Rocksmith shows up on 2014. None of the cdlc I downloaded today appears. IDK if this related but the transferred songs have a m.psarc and p.psarc file while the cdlc downloads only have p.psarc in my dlc file.