OK. Solved ! XD I wrote a new sketch simple as possible. then I pushed upload button and immediately I made a board reset. (During these few seconds it is connected on port9, I suppose) Arduino IDE was be able to upload that sketch to the board. After that I made a new reset of the board and the COM association is came back normal (few seconds on COM9 and then keep up on COM8) and the new sketch work fine (I can see messages on port monitor). So I can tell you the problem is in my original sketch that, in some way break the connection.Thank you all guys again for supportAlberto
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