Hi Christian,.
still not much to natolii I can say; I have two clones, but not so long that I had observed such a thing.
gallaensis I in the second season and you apparently like to cast out in the winter (Dec/Jan); whether they also expose an entire year, I don't know.
When someone, who once vonn me a rel great operculatus (about 3-4 cm diameter, ca 15 cm long) has gotten, it took 14 months, until it is again driven out...
It is but more extreme; in July 2011, I've got once 3 cicatricifer tubers that several years in a row had shown by swelling of the buds that they wanted, but exorcise after transplanting are they stuck then again and again and not driven out, which I then have stored dry again. The first has made a sheet in the last year in February, almost 7 years after I got it.
Happy growing, Bernhard.