Pinephone: Failed to mount root partition when using full disk encryption.

When using pmbootstrap with the --fde option, the boot process fails after unlocking the LUKS partition with the error "Failed to mount root partition."

Expected behavior: Power on device, enter password, continue to boot.

Actual behavior: Power on device, enter password, fail to boot with message "Failed to mount root partition."

Steps to reproduce: Install on sd card by using pmbootstrap --fde --sdcard=/dev/mmcblk(...) Insert into phone and power on device.

I'm new to PMOS and linux on a mobile in general, but I will be happy to provide any relevant info or debugging output if instructed how to.