Picoway Resolve - 4th less effective than 3 before it. Front desk says it's because I don't have as much pigment now. (photos)

I usually have to hide away for at least 3 days and have to put on makeup for a week till I'm comfortable going out bare faced. This last treatment was done by a different/new nurse and she had a few calibration issues with the machine while working on me. I walked out from the appointment looking only flushed when in the past I felt like I had blistering. I am concerned that the last treatment wasn't done correctly and the $800 spent on that single session was a waste.