Hello I installed Fedora 30 using my MacBook Air in BIOS mode by booting the LiveCD in "Windows" while holding down the "alt option" key.

I installed Fedora 30 to a portable external hard drive. So that I can boot Fedora 30 on my MacBook Air or my headless desktop PC.

I installed Fedora 30 using the standard partition and after installation completed successfully the MacBook Air is not able to detect the Fedora 30 installation when holding down the "alt option" key on my MacBook Air. I should see a "windows" icon at boot selection on my MacBook Air but nothing is showing up.

When I install other linux distributions such as Ubuntu 19.04 in BIOS mode on a portable external hard drive using my MacBook Air and after installation completed, I'm able to boot Ubuntu 19.04 on my MacBook Air using the "alt option" key and I'm also able to boot it on my headless desktop PC.

The fresh install of Ubuntu 19.04 in BIOS mode on a portable external hard drive can be booted both MacBook Air and headless desktop PC. With no modifications, works straight out the box like a charm.

My question is why cant Fedora 30 accomplish the same task? Seems like I need to use "rEFInd" which i DO NOT want to use.
If Ubuntu 19.04 can boot both MacBook Air and PC desktop, I'm sure Fedora 30 can do too.

So how can I accomplish this task? Seems like the grub installed in Fedora 30 in BIOS/Legacy mode is broken.