justify in the new editor

The justify button was actually removed from the old editor in WordPress 4.7. It was thus not migrated to the new editor at all.

Ok, I use WP Edit.
But if changed in HTML-Mode to justify it will ignored!

use ctlr + shift + j its what i always use, and it works

While that keyboard shortcut will work, it will only work for a Classic Block, not for any other normal blocks in the editor.