There are a lot of overlapping numbers. I'm not a PHEV owner, but your 50% charge level might refer to your total battery charge (it is actually less as there is a "buffer"). The 6 mile estimate would just be the remaining initial plug in charge. Those are two different concepts. Takes a while to wrap your head around it. The battery contains both your plug in charge and the HEV minimum in one pot. Those numbers are just different ways to visualize the same exact state of charge.
2018 Kia LX HEV Metal Stream with Advanced Tech