Maybe it's a new one
I haven't seen it before either!
Yes, when you turn off your E8 it seems like you can't press the keys. But the truth is you can never actually press them, all you feel when it's turned on is haptics feedback, and the keys themself are touch-sensitive keys.
So, when you turn it off, press and hold where the * and # buttons would be when it's on, and while holding down, pull the power switch until the bootloader shows up
First, you MUST make a backup, because I really think that's a new firmware