Have similar issue. Kindle 2024 11th gen.
I have been running installation commands on
https://github.com/finlater/kindlebtcontroller.koplugin which also includes that udevadm trigger. And since that time the kindle's lab126 framework crashes into white screen when i try to boot.
What I did then:
1. Since i have had koreader installed and a running ssh server, that allowed me to still open KoReader from ssh.
2. But when i closed KOReader and waited for a few minutes, the kindle shows a "Critical error troubleshooting" screen. It allows deregistering device from amazon or reset kindle also promoting contacting customer service.
3. I did backup of my files over ssh/scp and decided to do factory reset.
4. Did the factory reset. Yet after reboot it still shows white screen with brightness leds.
Now:
I can't access file system over usb. However upon force restart with usb plugged in kindle shows up in file explorer for a moment and disappears.
So if you have ssh/koreader access, don't do factory reset - it won't help.