Why is the domain name missing from the logout redirect?

My development computer recently had to be rebuilt so I am now trying to migrate a WordPress site from the hosting company to my development PC. So far I have done this:

Installed XAMPP.

Download the PHP files using FTP and put them in htdocsmysite

Create a virtual host called: localhost.MySite.

Export the .sql from the host using PHPMyAdmin

Open the .sql and to a find and replace replacing: www.mysite.co.uk with: localhost.MySite

Use PHPMyAdmin on my local PC to load the .sql

Make changes to wp_config.php:

Everything appeared to work e.g. the multi sites; the admin panel etc. The only issue I have is when I logout of the admin panel; I am redirected to: http://wp-login.php/?loggedout=true instead of: http://localhost.MySite/wp-login.php/?loggedout=true. What can I do?

I have spent a while Googling this e.g. I have looked here: https://wordpress.org/support/topic/logout-redirect-not-working-3/page/2/

This issue does not happen on the live website.

Update

I only appear to have theis issue on the root site of the multi site.