We all make mistakes, including me.
On Geyl and Parthenope BOTH the increases are incorrectly charted. I know, I know...I said to think of the little black square as your stitch marker, which would be fine except you have to swap it with the yo increase. They should read:
slip marker, yarn over, work across row in pattern, yarn over, slip marker, knit one (this is the ONE stitch that the increases will fall on either side of). The markers mark the ONE stitch (stop me from finding a way to make a "one ring" joke, please, stop me!) and nothing else. There will only ever be the ONE stitch between the markers. The yarn overs feed into the main pattern section. Otherwise you'd have to be moving markers arond every time you added a new pattern repeat in and no one wants to do that. Yuck.