Tracking subdomain not working right?

I have http://www.domain.com and blog.domain.com. blog is my WP site that I have this plugin on, and www is my non-WP store. Both have the GA code installed and generally are tracking things.

I’m having a couple main problems.

#1 – The Search Console reports in GA are missing all traffic for blog.domain.com.

#2 – For all other reports the subdomain traffic shows, but I have no way of differentiating subdomain traffic from mainsite traffic.

This help page suggests that all I need to do for a subdomain is exclude the subdomain as a referral source.

https://www.monsterinsights.com/docs/setup-subdomain-tracking/

On the plugin’s Advanced tab there is a field for subdomain tracking. What do I enter here, blog.domain.com or just blog? Or nothing? Will this solve my two problems?

Google’s GA help seems to suggest I don’t need to do anything at all and can use the same tracking code on both sites. But there’s something I’m missing.

Perhaps I should be creating an entirely new GA Property for blog.domain.com? I tried creating a new GA View, but it seemed to just duplicate all the stats.

Sorry for the long post, but i’m trying to convey how I have been trying to fix this issue myself for a few weeks.

https://wordpress.org/plugins/google-analytics-for-wordpress/