If you are subscribed to Stathead for a single sport (Baseball, Football, Hockey, Basketball, Soccer), then you will only have ad-free browsing on the selected site (i.e. a Baseball subscription gives you ad-free browsing on Baseball-Reference.com and anything on https://stathead.com/baseball/).
If you are an All Sports Stathead subscriber, you should have ad-free browsing on all our sites (including our college football and basketball sites).
If you are still seeing ads on sites you are subscribed to, there's two likely issues that might be causing this:
First, you might be logged out of your account, and to remove the ads, you must be logged into your Stathead account while on the reference pages. To check this, please look at the top right corner of the page and make sure it says "Welcome [nameXXX]". If not, click Login there and then see if you're no longer seeing ads on the page.
Second, you might have an old expired cookie on one of your devices that is marking you as a non-subscriber. To fix this, can you please logout of all your devices, and then login again to reset the cookie? If that doesn't work, please try clearing your cookies. Also, you might need to refresh the page again even after you've logged in.