Mechanical timing

[osal]

I was checking if my cam timing was correct and after many revolutions i got the markings on the cam sprockets and chain to align at TDC as seen below.


However i noticed that the lower timing chain marks do not align with the yellow marking as seen below.


I would have thought that since the timing on the upper chain is correct, the timing on the lower chain would be too. Is this true? or are they not related?
I did my search but could not really find the answer to this.

Thanks