I am assuming your SSD is external, as is mine. I should add that if that is the case, most readers here will not understand that. Some bioses have that issue. My asus is one fine example of this. On my asus, I need to press esc every time it boots to bring up the boot selection method. It takes just a little getting use to, but is worth it.
If BIOS can boot to it manually it [almost certainly] can boot to it automatically. It's just a case of working out what needs kicking. Many motherboards have multiple disk controllers (with some being third party that get a much lower boot priority). It might be worth moving to another controller if you can and seeing if that allows you to select the correct drive.
Anyway, failing that and as a very distant workaround, you could install Grub (the bootloader) onto other devices... Like a small USB drive. Then make that the bootable device.
But seriously, I'd take this up with the Motherboard/SSD manufacturers before getting that far.
