Battery degradation ... or better the assumption of the PHEV BMU battery degradation can be seen only with an OBD2 adapter and the PhevWatchDog or EVBatMonitor application.
EV range is a function of the state of charge, state of health, temperature of the battery, and the driving "style" in the last car usage
Note that by clicking on AC .. EV range is decrised by around 30%
If your last drive was done in pure EV mode, normally the EV range is relative accurate, but if the previous drive(s) are done with a combination of EV and petrol ... the EV range after a full charge can be very unprecise (in my case it was always too optimistic the EV range after I used the PHEV with the support of the ICE)
I suggest to invest into a decent OBD2 adapter, and use the watchDog application .. this will allows you to get a perfect stuatus of your car