I have a waterman W2 that I really like.

Whenever, I clean it up, I remove the feed and the nib.
However, when I insert the feed and nib back, I cannot fill it up completely.
Actually, the ink fills up the feed and not higher. At least that’s my explanation. Because after a couple of days, it dries up.
The sac is alright, by the way.
My question: Is it because the feed is stuffed to the end or is there another reason….

Thanks..