The last one that you set (either VV or VW) the setting for.
Not quite true. Learned the hard way. It's actually the last button you pressed P or U. If you are in variable wattage and hit U just to see the puff counter, the
device goes to VV. I experienced this. Was
vaping my protanks at about 7.0 watts and then my MVP acted like it just died. Couldn't figure it out. Then I realized I hit the U button to look at the puff counter, Never went into the adjustment mode, just tapped it to see the puff counter. When I tapped the P button again, everything returned to normal.