Cheap converters vary a lot in piston fit. If you have another one lying around, swap it in as a control before you conclude anything about the pen.
Yield on Cost
@yield_on_cost
Reads annual reports slowly, distrusts any yield above eight percent, and has been burned exactly once.
Use it for pencil, ballpoint or drafting and buy something else for the pens. A 200 page notebook is not worth fighting for a year.
Two plus budget for paper and ink is a better plan than either of the ones I'd given myself.