I wonder if this is a question that is being obscured by translation.
When Papity changes a style later in the song using F5, he/she writes: "Band in a Box only reminds the first bar style and play it along the whole song" (my emphasis added)
Dan (username MusicStudent) said, and I can verify, that the track names in the Mixer do not change when the style changes. I hear the style change but I don't see anything change in the mixer. Whole new instruments might be playing.
Is that the question here? That the style change works but you don't see visual evidence of that?
And is this really Multisyles, or choosing another style? Papity, you can upload your song (MGU or SGU file) to a free place like Dropbox, put it in a Public area, and post a link to the song here. Then as Dan suggested, we will know for certain.
I apologise for my bad english, but I am asking for help in both forums, english and french (my mothertongue), to maximise my chances to find a solution.
You are absolutely right about the bad use of the term "reminds", I should have written "keeps" or something similar.
I will try to explain the situation in a few words.
This is not about multistyles but well about changing styles.
It is not about visual evidence of changing styles but well about styles (audio) that don't change when they should.
I guess the problem comes from a bad setting I "applied" somewhere, but where ?
Could that be in the Midi/Audio Driver Setup ?
NB: The track name doesn't change in the mixer when the style changes, but it changes in the black rectangle below the title of the song, I have seen it a week ago before my problem appeared.