I try to explain the prob, that is not very clear,
when my phone power off because of battery down, I attach the charger cable and aspect that my FP3 show the images that appears when I attach it with battery cable.
But nothing appens…
I need to detach it
open the rear protection
remove and reinstall battery
then, when I attach the cable again… it start to show the screen images and start to charge.
Does this mean that you let the battery run all dry until the percentage was 0 %? That’s something not recommended to do because it can reduce the total battery life expectancy. And it might result in such “behaviour” as the one you are describing.
It’s not exact science. Try to not let it run below 20%, but the phone/battery will not spontaneously combust if you do occasionally.
0% is really bad, as you found out already, don’t let it run to 0%.