Asus VivoBook 15 with a 512 GB NVMe M.2 with Windows 10 preinstalled.
A 1 TB Samsung SSD was added.
Anaconda was run and Fedora 33 was installed.
Windows EFI Partition was mounted on /boot/efi.
SSD was setup with just BTRFS volume and swap.
BTRFS mounts / and /boot.
After installation, Fedora booted perfectly,
Windows runs smoothly too.
But…
after closing Windows when booting again, GRUB doesn’t show the Fedora options.
UEFI setup must be opened and go to the boot options and and select Fedora.
Then both Fedora and Windows are shown.
And rebooting or starting up after closing Fedora shows both booting options.
I guess the ext4 partition for /boot was missing, @computersavvy.
I took advantage to restructure the partitions structure and split Fedora into two drives, an NVMe M.2 for both Windows 10 and Fedora system files and a SSD for also both Windows 10 and Fedora Data.
After installing and resetting the appropriate information was displayed in the GRUB menu.