Case sensitivity problem on IIS after installing IIS mod rewrite

I have wordpress running on IIS on a Windows Server.
Today I installed IIS Mod Rewrite so that I could remove the index.php from my permalinks.
Everything is now working fine with the permalinks.

However, suddenly my website has become case sensitive.

https://www.chinaonecall.com/news works fine but https://www.chinaonecall.com/News goes to a wordpress “page not found” message.

My .htaccess file looks like this:

# BEGIN WordPress
RewriteEngine On

RewriteRule ^/news/index.php/(.+)$ https://www.chinaonecall.com/news/$1 [R=301,L,NC]

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule . index.php [L]

# END WordPress

I can’t work out how to make https://www.chinaonecall.com/News redirect to https://www.chinaonecall.com/news

Any ideas?