Hello,
I've come with a new idea : the over current situation !
According to the datasheet, in such a case : "softstart is commanded, and all outputs are turned off until the high current condition is removed" do you think that it coul'd explain ??
At startup, are outputs still off or can spikes occur on them ? It might also be toggle on pin 6
Because in this case it coul'd explain: in one way, some transistors combination give me more current than limit -> the chip resets -> the frequency feedback (Tach-out) get mad...
Thank you for any suggestion / idea / confirmation :)