Awesome, you just gave me an idea and it worked.
The problem wasn’t exactly what you described, but when you mentioned the first frame it occurred to me that perhaps AE really needs the true frame 0 in order to read motion vectors, I was rendering from frame 12 (in C4D) onward as I didn’t need the first frames.
I went back to Cinema and rendered from frame 0 and this time al the channels appeared correctly, all I need to do now is trim the excess frames in AE and everything is good as usual.
Thanks a lot for your help Walter.
D.