Gutenberg is still new and there are many plugins that are not still supported. The Amazon Associate Link Builder plugin from the Amazon's official Chanel also are not compatible with it.
They do not have an estimated date when they will update it or ever they will do it.Solution:
Right now you can install the classic editor plugin (https://wordpress.org/plugins/classic-editor/
) and it will bring back the old editor panel with all the custom blocks you had, including the AAL search box.