Same issue here. It's the Brighthouse ad.
Seems like we're all having the same issue. The ad takes up so much of the screen it's difficult to navigate to My Portfolio. The My Portfolio tool is why I use Seeking Alpha. If this issue is not fixed I will leave and use another site.
SA's content is dominated by an that suddenly appears and covers 2/3 of the viewable page. It covers the link to my marketplace subscription. Even when I scroll down it stays active over approx 3/8 of the page. As a rule of thumb, when I visit a site that has this type of ad I immediately leave.
Almost as bad here. Very intrusive. Makes it much more difficult to navigate the site.