Unable to launch 4.1 installer: missing squashfs support

I am attempting to start the Qubes installer from a USB drive on a Lenovo ThinkPad P1 Gen4 (the model with a discrete GPU). I have secure boot disabled and am able to reach the Qubes GRUB menu. When I choose to boot the installer, it loads until the Basic System target, then prints the following errors:

systemd-gpt-auto-generator[1115]: EFI loader partition unknown, exiting.
systemd-gpt-auto-generator[1115]: (The boot loader did not set EFI variable LoaderDevicePartUUID.)
dracut-initqueue[1192]: mount: /run/install/repo: WARNING: device write-protected, mounted read-only.
dracut-initqueue[1177]: /lib/anaconda-lib.sh: line 71: shift: 2: shift count out of range
loop: module loaded
unable to read id index table
dracut-initqueue[1262]: mount: /run/initramfs/squashfs: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.
dracut: FATAL: Failed to find a root filesystem in /run/install/repo/LiveOS/squashfs.img.
dracut: Refusing to continue

I have verified the image is signed and the hash is correct. I have written the ISO to two USB devices with differing methods (DD from linux, DD in Rufus, etc) and both exhibit the same behavior. The NVME drive I am going to install this to does not have a previous version of Qubes installed. Any ideas?