WordPress migration

I added a subdomain in the same server and tried to move WordPress.
Each page was displayed without any problem, but the header section pull-down menu (one image) looked a bit different (second image)
How can I get back to the pull-down menu like the first one?

First piece

Second piece

・ Migration work done here
・ Because the theme and WordPress data did not move well, import from the migration source to the migration destination using the "All-in-One WP Migration" plug-in
(All-in-One WP Migration File Extension was installed and applied because the upper limit was small when importing)

Software plug-in used (FW/tool version etc.)

Windows10 64bit
GoogleChrome (Ver78.0.3904.108)

All-in-One WP Migration 7.10
(All-in-One WP Migration File Extension1.5)


There was no HTML code and CSS was new and old only

@ charset "utf-8";
/ *
Theme Name: Lightning Child
Theme URI:  URL of the official website of the theme (may be blank) 
Template: lightning
Description:  Theme description (may be blank) 
Author:  Name of theme creator (may be blank) 
Version: 0.1.2

The theme itself is a child theme that duplicates the template "Lightning".