Unable to install 7.0 release

[escoand]

What Happened?

I'm trying to install release 7.0 Horus but neither UEFI nor BIOS mode generates a working installation.

UEFI

The installation seems to be fine but the BIOS is unable to find a boot entry.

$ sudo bootctl list --esp-path /mnt
No boot loader entries found.

The directory contains EFI/ubuntu/... and EFI/BOOT/... with many .efi files.

BIOS

The installation crashes with something like this: https://superuser.com/questions/903112/grub2-install-this-gpt-partition-label-contains-no-bios-boot-partition.
I tried to edit the partition labels with gedit but didn't find the correct one to satisfy this step.

Steps to Reproduce

1. write iso to usb stick
2. advanced installation
3. select /dev/sda1 as boot partition
4. select /dev/sda2 as root partition

Expected Behavior

any of the boot environments should create a working installation

OS Version

7.x (Early Access)

Software Version

Latest release (I have run all updates)

Log Output

No response

Hardware Info

No response