Bad route appended to URL when redirecting from http to https

I have a WordPress site hosted on OVH and I'm having issues when redirecting from http to https.

http://www.example.com redirects nicely to https://www.example.com

https://www.example.com redirects nicely to https://example.com

However http://example.com redirects to https://example.com/www.

I don't know where this extra www is coming from.

My .htaccess looks like this:

<IfModule mod_rewrite.c>RewriteEngine OnRewriteCond %{HTTPS} offRewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]</IfModule>