Going through the GUI installer selecting all the defaults, and install with LVM and ecryption, AND for the normal option without encryption I get these errors on TWO different laptops, both ~10 years old with BIOS.

Encrypted:

Installing for i386-pc  platform.
grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
grub-install: error: embedding is not possible, but this is required for RAID and LVM install.

Unencrypted:

Installing for i386-pc  platform.
grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
grub-install: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists. However, blocklists are UNRELIABLE and their use is discouraged..
grub-install: error: will not proceed with blocklists.