German wiki to the Doges of Genova counts the Visconti time in Genova 1421-1425 like this ...
Unter der Herrschaft von Filippo Maria Visconti, Herzog von Mailand: 1421–1435
1421–1422: Francesco Bussone (= Carmagnola)
17. Januar(?) 1422–31. März 1422: Urbano di Sant'Alosio
5. Dezember 1422–1424: Francesco Bussone (= Carmagnola)
15. November 1424–1428: Giacomo degli Isolani, Kardinal
1428–1432: Bartolomeo Capra, Erzbischof von Mailand
1432–(?): Oldrado di Lampugnano
1434(?)–1435: Oppizino di Alzate
1432(?): Francesco Barbavara
25. Dezember 1435: Erasmo Trivulzio
Isnardo Guarco: 28. März 1436–3. April 1436
Carmagnola in November 1424 creates a hateful scene in Abbiategrasso, the precise date in this month is not known to me. The consequence of the action demands, that Carmamagnola has to to escape from Milanese territory as quick as possible. 15. November 1424 (see above) is given as start for the installment of Giacomo degli Isolani, Kardinal. Perhaps one can assume in this situation, that Giacomo degli Isolani was installed after the hatefull action of Carmagnola, but possible is also, that Carmagnola was in a rage cause Giacomo degli Isolani got his job.
Giacoma Isolani has a biography here, it doesn't explain the month November 1424
https://it.wikipedia.org/wiki/Giacomo_Isolani
https://www.wandruszka-genealogie.eu/An ... solani.pdf
This explains more, but I don't understand it completely. I translated a part with the translation automat:
1420 between the duke and Florence had assigned Bologna and the
Romagna to Florentine influence, in March 1422 the Visconti made an agreement with
papal legate in Bologna, in May 1423 he secured control of Forlì and in
June made Anton Galeazzo Bentivoglio, an emerging figure in Bologna, one of his
ally. The risk that the city was included in the Visconti domain became concrete e
Rinaldo degli Albizzi, Florentine ambassador to Bologna, gave worried notice
to his own government, citing as the source or, perhaps, as the inspiration of the Visconti designs
the., "provisioned" by the duke. However, the Duke's interest and resources were soon turned
to other objectives; therefore the threat on Bologna and also the commitment of the I. (= Isolani) it was
addressed to other purposes. Between July and October 1424 the I. he was at the Papal Curia in
occasion of a peace conference promoted by Martin V. At the preparatory talks,
interesting the clash between Florence and Milan, the I. (= Isolani) in robe,
it would seem, more as a collaborator of the pope than as a Visconti representative. But the
his bond with the duke had not ceased, so much so that in October 1424, when already
the failure of Martin V's initiative was looming, his assumption was taken for granted
to a high post in the Visconti administration. In fact, in early November,
relieved Francesco Bussone (Carmagnola) from the post of governor of Genoa,
in view of the command of a military expedition against the Kingdom of Naples, the Visconti
he appointed the I. (= Isolani) to succeed him, who on 15 November entered Genoa as governor. TO
Genoa the latest events, culminating in the limited success of the expedition
against Naples of the Genoese fleet, entrusted by Visconti not to an admiral
Genoese but to Guido Torelli, they had rekindled the dissent towards the duke
from Milan.
"In fact, in early November,
relieved Francesco Bussone (Carmagnola) from the post of governor of Genoa,
in view of the command of a military expedition against the Kingdom of Naples, the Visconti
he appointed the I. (= Isolani) to succeed him, who on 15 November entered Genoa as governor
This sounds, as if Carmagnola had the condottieri commission to attack Naples.
English wiki (Bussone) tells:
"Soon the whole duchy was brought once more under Visconti's sway. But Filippo Maria, although he rewarded Carmagnola generously, feared that he might become a danger to himself, and instead of giving him further military commands made him governor of Genoa. Carmagnola felt greatly aggrieved, and failing to obtain a personal interview with the duke, threw up his commission and offered his services to the Venetians (1425)."
Similar it is interpreted by others.
If this is would be correct, then one should think, that Carmagnola was happy to get the job to attack Naples. But Carmagnola, as we know, isn't happy. There is a big contradiction.
Treccani.it has the clarifying information:
Per quanto se ne sappia il B., tuttavia, non protestò, e lasciata la carica di governatore partì da Genova il 5 ott. 1424, sicuro di assumere il comando di una nuova armata destinata alla Puglia. Ma la spedizione venne annullata un mese dopo. È senza dubbio leggenda il racconto del Biglia secondo il quale ad Abbiate il B. fu protagonista di una scena tempestosa quando il duca rifiutò di riceverlo; ma è certo, tuttavia, che egli si trovò allora senza una carica, senza un comando, tenuto lontano dal duca da persone della cui gelosa ostilità doveva essere ben conscio, e senza alcuna sicura prospettiva per il futuro.
Automatic translation:
As far as we know, the B., however, did not protest, and left the office of governor he left Genoa on 5 October. 1424, confident of taking command of a new army destined for Puglia. But the expedition was canceled a month later. Biglia's story is undoubtedly legendary, according to which B. was the protagonist of a stormy scene in Abbiate when the duke refused to receive him; but it is certain, nevertheless, that he found himself then without a position, without a command, kept away from the duke by people of whose jealous hostility he must have been well aware, and without any sure prospect for the future.
This description makes sense. Carmagnola simply was cheated with a promise, which wasn't fulfilled.