I have a combo espresso/coffee machine and I’ve been trying to make a decent cappuccino but I’ve had no luck so far. I make my espresso and then flip the switch from espresso to froth and wait for it to heat and then turn up the steam knob but if any steam comes out at all it comes from the espresso drip.. not the frothing device or even the steam tube. I’ve tried to steam the milk without making espresso first but the same thing happens. Any advice?