I see you are using Eclat de Saphir, which is a wet ink. But it is not a lubricating ink. You may want to try a more lubricating ink such as one of the Monteverde inks (Sapphire Blue or Horizon Blue is nice), or perhaps a Sailor ink such as Souten.
I might suggest that before you "tinker" , try to write through two fills of a lubricating type of ink through the pen. If it still feels the same way, you may want to send the pen back.
I have had a couple of pens with similar problems. I have found that unless the nib has major baby's bottom or other issues, that if I just write with a lubricating type of ink for a while the pen seems to "break in".
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