Google AdSense Notifications suggested I try out Google’s new official WordPress plugin: Site Kit.
I already have AdSense working fine on all of my sites. But, I decided to try Site Kit on one.
When you set up AdSense Site Kit, be sure you finish following all of the steps. You get Congratulations! messages for finishing steps along the way, but you are not really completely done. If you want ads to show so that you can earn money, you have to completely set up and connect AdSense once you have Site Kit successfully installed.