Hi,
I recently bought a Cobalt Blue Estie and an MV Adaptor (comes with a special converter) so I can use my old nibs. The whole thing fits nicely. I inked the pen (Iroshizuku Asa-gao) and it was great until the nib stopped writing. At first I didn't think much of it since the pen was sitting around without the cap for a while. I pushed some ink into the feed (turning converter piston) and it worked again. Just having the pen sitting nib down for a while, even on a paper towel, does not help. Ink has to actively be pushed into the feed.
It seems there is no ink flow to