That would be your BIOS OS selector.
Since you don’t see any menu after selecting to boot to Manjaro, i suppose the GRUB menu – this is what @brahma was talking about – is hidden: [HowTo] Reach a minimal system
That would be your BIOS OS selector.
Since you don’t see any menu after selecting to boot to Manjaro, i suppose the GRUB menu – this is what @brahma was talking about – is hidden: [HowTo] Reach a minimal system