This is not important, but why Manjaro boot screen is black? Should boot screen show something, example Manjaro-logo?
Computer boot normal and works good.
There is no logo by default. If you motherboard manufacturer has a logo, it will display.
Otherwise, you can install bootsplash-manager to install a theme like bootsplash-theme-manjaro. Alternatively there is plymouth with a theme like plymouth-theme-manjaro.