Perhaps an issue with the TPM, try disabling it to see whether it boots up.

You are going to need to run a rescue system to get this sorted, for example from an USB stick. Usually you can enter UEFI setup by just spamming the button on boot (F2, F12, F10, Del, look up what your system uses). If that doesn’t work you can either reset the BIOS settings, using the jumper or button (see manual again, removing the battery is internet lore and almost never required, just use the jumper). Another option is to remove your boot drive, that will prevent fastboot from working, so the next boot will be a regular one.

I had this issue and it was because I told grub to support dual booting from two different disk drives (one of them USB) and then I removed the USB drive. Linux-boi still tried to enforce booting from the now not-connected drive.

I can’t remember exactly what I did, but there may be something about a systemd unit which can be removed/disabled - or maybe I did some fishing around in fstab to remove the drive it thought should exist but wouldn’t always (and then probably did an update-initramfs -u or similar.

Do you have GRUB? If yes you can edit your kernel command line and append “init=/bin/bash”, see if at least this gives you a prompt, this has saved me a couple of time in the past. Else booting on a USB and mounting your boot partition may help to fix it.

BTW I also have LUKS and I’m using TPM, using tpm2-initramfs-tool, first, it failed because I forgot the tpm modules in initrd, but I always have 2 kernels installed and only modify one initrd at a time to have a safe boot if I have a problem, like I had!

I tested tpm2-initramfs-tool with proper tpm2 modules and it worked.

I also tested with clevis-initramfs and clevis-tpm2 and it’s even easier, no messing with crypttab.

Also, as long as you can break GRUB and append “init=/bin/bash” it is not secure of course, you can then prevent grub editing or not using grub at all.

I had this same error a few months ago when a drive was failing to mount because (unbeknownst to me) it was overheating. I turned the system off for a few hours before troubleshooting (I had errands to run). When I came back, the system booted without issue.

If you’re looking for an easy troubleshooting step, have you tried turning off the system for several minutes (and unplugging it) and then powering it back on?