

Interesting. Looks like perhaps your boot loader isn’t properly pointing at your root partition.
I’m assuming you’ve just done the install and never successfully booted, yes? In that case, you can try to re-run the installer, or try rescue mode and try repairing the bootloader.
Are you doing dual-booting, or is this system dedicated to Linux?
I’m pretty sure certificates signed by internal CAs are exempt. I would have to go find the documentation but I believe that was called out.