My main website has the GA tracking code with subdomain tracking enabled.
ga('create', 'UA-XXXXXXXX-1', 'auto'); ga('require', 'displayfeatures'); ga('send', 'pageview');
A subdomain has GA tracking set with the same 'UA-XXXXXXXX-1'.
My main website has an iFrame with the subdomain's page as its source. In Google Tag Assistant, I can see the same tracking code listed twice with the message 'Same web property ID is tracked twice.'
Why is it being duplicated?