X1 Extreme Gen 2 Update and Black Screen

Have tried two different scenarios, a little stuck and unsure of how to proceed or debug this further, so looking for some guidance.

I have a Lenovo X1 Extreme G2 and attempting to update TPM firmware:

Upgrade available for TPM from 0.73.8 to 0.73.64
20QVCTO1WW must remain plugged into a power source for the duration of the update to avoid damage. Continue with update? [Y|n]:

Upon reboot, i see a boot logo, and top right left a System Reboot message (as seen in past successful updates). The laptop reboots and remains on a black screen (slightly illuminated). Fans are spinning and remain so. I have left this for hours without change. In the end, I forcefully pull the power and reboot as normal.

Initially I thought it might be something related to the update and hadn't had a chance to debug further, but I have also just attempted to update to a new BIOS with:

fwupdmgr install <file>

On reboot, i experienced the same issue.

I am running secure boot, and have disabled it from BIOS, booted from an unsigned image and attempted installation, but the same occurs, so it doesn't appear to be secure boot / signing related. I deleted the fwupd related entries/images in /boot and retried with the same outcome.

Not quite sure how to proceed debugging this, so looking for some guidance. The below is the output after running fwupdmgr install <file> and before the reboot.

fwupdmgr --version
client version: 1.6.0
compile-time dependency versions
        gusb:   0.3.6

daemon version: 1.6.0

BootNext: 0001
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000,0010,0011,0012,0013,0014,0015,0019,001A,001B,001C,001D,001E,001F,0020,0021,0022,0023,0001
Boot0000* Linux Boot Manager
Boot0001* Linux-Firmware-Updater
Boot0010  Setup
Boot0011  Boot Menu
Boot0012  Diagnostic Splash Screen
Boot0013  Lenovo Diagnostics
Boot0014  Regulatory Information
Boot0015  ThinkShield secure wipe
Boot0016  Startup Interrupt Menu
Boot0017  Rescue and Recovery
Boot0018  MEBx Hot Key
Boot0019* USB CD
Boot001A* USB FDD
Boot001B* NVMe0
Boot001C* NVMe1
Boot001D* ATA HDD0
Boot001E* ATA HDD1
Boot001F* USB HDD
Boot0020* PXE BOOT
Boot0021* LENOVO CLOUD
Boot0022  Other CD
Boot0023  Other HDD
Boot0024* IDER BOOT CDROM
Boot0025* IDER BOOT Floppy
Boot0026* ATA HDD
Boot0027* ATAPI CD

0abba7dc-e516-4167-bbf5-4d9d1c739416-fwupd-55d04ffc-714a-4457-b982-d244343e1958-0
0abba7dc-e516-4167-bbf5-4d9d1c739416-fwupd-ux-capsule

/boot
├── EFI
│   ├── arch
│   │   ├── fw
│   │   │   ├── fwupd-3b8c8162-188c-46a4-aec9-be43f1d65697.cap
│   │   │   └── fwupd-55d04ffc-714a-4457-b982-d244343e1958.cap
│   │   ├── fwupdx64.efi
│   │   ├── linux-signed.efi
│   │   └── linux-signed.efi.bak
│   ├── BOOT
│   │   └── BOOTX64.EFI
│   ├── Linux
│   └── systemd
│       └── systemd-bootx64.efi
├── initramfs-linux-fallback.img
├── initramfs-linux.img
├── intel-ucode.img
├── KeyTool-signed.efi
├── loader
│   ├── entries
│   │   ├── arch.conf
│   │   └── arch-signed.conf
│   ├── loader.conf
│   └── random-seed
└── vmlinuz-linux

fwupd / firmware-lenovo

X1 Extreme Gen 2 Update and Black Screen #124