Allow CORS for sub domains

I’m trying to allow all subdomains under my main domain to get assets from each other. Fx. mydomain.com and test.mydomain.com should be able to access cdn.mydomain.com without being blocked.

I found this SO question that covers it, but I can’t get it working… My “cdn.mydomain.com.conf” virtual host file looks like this;

<VirtualHost *:80>
	ServerName cdn.mydomain.com

	ServerAdmin admin@mydomain.com
	DocumentRoot /var/www/cdn

	# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
	# error, crit, alert, emerg.
	# It is also possible to configure the loglevel for particular
	# modules, e.g.
	#LogLevel info ssl:warn

	ErrorLog ${APACHE_LOG_DIR}/error.log
	CustomLog ${APACHE_LOG_DIR}/access.log combined
	
	#Header set Access-Control-Allow-Origin "*"
	
	<IfModule mod_rewrite.c>
	<IfModule mod_headers.c>
		SetEnvIf Origin ^(https?://(?:.+\.)?mydomain\.com(?::\d{1,5})?)$   CORS_ALLOW_ORIGIN=$1
		Header append Access-Control-Allow-Origin  %{CORS_ALLOW_ORIGIN}e   env=CORS_ALLOW_ORIGIN
		Header merge  Vary "Origin"
	</IfModule>
	</IfModule>
</VirtualHost>
<Directory /var/www/cdn>
	Options Indexes FollowSymLinks
	AllowOverride All
	Require all granted
</Directory>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

Is the “stolen” content from the SO-question placed in the right place? I still get;

Access to font at 'https://cdn.mydomain.com/test.ttf' from origin 'https://sub.mydomain.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

What am I missing?