I've had a PFM II for a while now and recently, say the last two fills so around a month or so, when I rotate the blind cap, the snorkel does not fully extend. It stops around halfway out.
There is sufficient snorkel protruding to gently pull it out to full extension and fill the pen. Winding it back in, it retracts fully.
The mechanism seems otherwise quite sound: no sense of tension or hesitancy when turning the blind cap in either direction, it feels quite smooth. Just for the last turn or so, the snorkel sits halfway out.
Is this indicative of imminent failure of a seal? Something else I should be concerned about?