Ink smudge on right side of paper
Chances are high that the process of clearing the jam has resulted in ink being released from the cleaning/resting pad area based over on the right hand side (where the printhead sits when not in use).
This waste ink has probable come into contact with the rollers and other parts over on the right edge of the paper.
You'll probably see this ink slowly fade out and disappear over time. If it doesn't however there's something effectively feeding things so check the resting pad for a loose tube, overflow, puddles, etc...
If there's anything like that, report back (preferably with images).