Well, surprise, surprise.
The led indicator light is now lit on my Libra 2 while charging and the device asleep after updating to this latest fw.
And while asleep and charging, the displayed battery percent changes accordingly.
Edit and Update:
Just to qualify my observation.
This is when charging using a PC/laptop connection without access to the device storage (cancelled usb connection).
When using a charger/adapter (I used Amazon charger from my Fire HD 10) the led flashes a few times and then die again.