Is there a problem with citing the original source instead of the source where the information was first found?
You are correctly citing the original source of the idea/quote (which you looked up and read in context, as you should). 

You don't (usually) have to cite the paper that exposed you to that original source. The purpose of a citation is to 


give credit to the originator of an idea/quote
tell readers where to look to verify your claims about that idea/quote


In this case, citing the original source satisfies both purposes and is sufficient.

An exception is a review paper, which doesn't add new research, but collects and comments on relevant sources on a subject. In this case, the curation of materials is the novel idea contributed by the review paper. If you then go on to use the collection of sources you found via that paper, it's often appropriate to cite the review paper also.

Similarly, if you use the interpretation of the original source found in the secondary source, you should also cite the secondary source.