I own a MB147 and I noticed that sometimes the ink cartridge loosens a bit interrupting a regular ink flow. This happened with Montblanc cartridges and also with other brands two three times in the past few months.
There's a little step in the cartridges holder (see photo) that is supposed to keep the cartridge in the right position but looks it like is not serving is purpose anymore with the same level of reliability it was used to.
I bought this pen many years ago and this looks like a new issue for me. Is anybody else experimenting the same problem? Solutions?