Although the manual installation detects the EFI partition and adds the Ubuntu bits
ubuntu@ubuntu:/mnt/EFI/BOOT$ ls -la total 1855 drwxr-xr-x 2 root root 512 janv. 7 15:55 . drwxr-xr-x 5 root root 512 janv. 7 15:55 .. -rwxr-xr-x 1 root root 955656 janv. 7 16:06 BOOTX64.EFI -rwxr-xr-x 1 root root 85672 janv. 7 16:06 fbx64.efi -rwxr-xr-x 1 root root 856232 janv. 7 16:06 mmx64.efi ubuntu@ubuntu:/mnt/EFI/BOOT$
Although the manual installation detects the EFI partition and adds the Ubuntu bits
ubuntu@ ubuntu: /mnt/EFI/ BOOT$ ls -la ubuntu: /mnt/EFI/ BOOT$
total 1855
drwxr-xr-x 2 root root 512 janv. 7 15:55 .
drwxr-xr-x 5 root root 512 janv. 7 15:55 ..
-rwxr-xr-x 1 root root 955656 janv. 7 16:06 BOOTX64.EFI
-rwxr-xr-x 1 root root 85672 janv. 7 16:06 fbx64.efi
-rwxr-xr-x 1 root root 856232 janv. 7 16:06 mmx64.efi
ubuntu@