I have confirmed an annoying behaviour of P7Pro after each upgrade started few months ago. Following an upgrade requested reboot it cannot be wirelessly charged before being fully charged and discharged several times using wired charger. Actually it is just discharging faster than charging with 80-98% of battery consumed by "System".
I am using charge optimisation and I've noticed that the crazy discharge stopped after I see a shield icon on the battery following a charge. How to get to it I am not sure, last time it required few days. I cannot just stop using it and let it discharge and charge, so may be it needs just couple of full cycles, yet I don't know what full cycle would be.
During my observations I have not installed or removed any applications, nor I was changing my habits on how I use it.