Cannot connect AdSense

This is by far the most protracted plugin installation I’ve ever done. I’ve spent over two hours to get it working (had to disable modsec and redirect all http requests to https) and now I am having issues connecting Adsense. It asks me to create an AdSense account but I already have one. Clicking on the “Create…” button opens my AdSense account and returns a message saying “You already have an AdSense account associated with…” but the plugin still fails to connect. How do I get out of this loop? All other services are connected.