Screen goes completely dark after boot menu (after installing full-disk encryption)

My goal: install Ubuntu Desktop with full disk encryption (lvm or zfs) on an Asus NUC 14 Pro+ (Ubuntu IDs it as NUC14RVS-B with Intel Core Ultra 7 155H CPU).

What works: Installing Ubuntu without full disk encryption, using the same LiveCD and hardware.

What doesn't work: Booting up (post bootloader) after having installed full-disk encrypted Ubuntu. Screen goes black (completely, no cursor, no purple etc).

I have a LiveCD usb with ubuntu-24.04.1-desktop-amd64 (checked for correct checksum).

The LiveCD boots just fine and allows me to install (unencrypted) Ubuntu via the default settings (install third party/media codecs checked) and "erase everything" option. It finishes and boots fine after reboot.

If I do the same thing again and select the default option but only change to "advanced options" Full Disk Encryption (ZFS or LVM has same problem) the installation finishes with an OK message. After restart and remove the liveCD I am shown a boot menu with Ubuntu at the top but when I select it the screen just turns dark (but computer seems to be running still). The same thing happen if I select Ubuntu Advanced Options and boot into the Recovery Mode.

If I boot into the LiveCD again I can decrypt the drive just fine and mount it.

Gparted shows me the LiveCD has created three partitions on disk. fat32 /boot/efi (boot, esp flag), ext4 /boot and [Encrypted] on /.

The display is an Apple Studio Display connected via thunderbolt if that matters.

I have turned off SecureBoot and allowed 3rd party UEFI in the BIOS.

I have tried editing grub to boot it with nomodeset nouveau.modeset=0 i915.modeset=0 but no luck.

Any suggestions for what I should try next?

EDIT Narrowed down the issue further, it only happens when booting with the Studio Display over thunderbolt connected. Connected it to another display with HDMI and that boots up well with no issues.