Smells like an .htaccess thing. Have you replaced the contents of .htaccess with the ones provided by WordPress? Also, according to the Codex, you may need to add Options FollowSymlinks at the start of the file.
Multisite Sub-domain creation Doubt | what will be the document root folder?
Put this code at the beginning of the .htaccess file. Options +FollowSymLinks RewriteEngine On RewriteRule ^abcd/(.*)$ /zxcv/$1 [R=301,NC,L]
Prefix Multisite Directory Structure
If your nginx server block is handling multiple domains, the simplest solution would be to test the $host parameter within an if block. Also, change the rewrite statement so that it only matches a single URI. For example: if ($host = domain.com) { rewrite ^/$ https://new-domain.com permanent; } This is placed near the top of … Read more
WordPress Multisite Redirection Issue
Multisite Subdirectory with same domain subdomain
Link structure, WordPress IIS
How can i redirect my Blog to a Subdomain?
When changing to SSL, be sure to edit your wp-admin > Settings > General > WordPress Address (URL) and Site Address (URL) values to include https. If still having troubles the media items (I believe) are built with site_url or home values (mentioned above) in _options. Verify they’re https, then check out if you have … Read more