5V at the USB port without connection to PC

Please send me any suggestion or special request about this in order to fix it as soon as possible,

Thank you, Gianluca - but we have already.
A very low voltage P-MOSFET will in fact NOT work better with a non-rail to rail comparator. As the current comparator will never exceed 3.7V the FET MUST close at -1.3V which the new one does not!