For Ferlew: To get around the problem in Firefox of websites still thinking that you've go an ad-blocker enabled when you haven't, on a site where it's happening click on the small shield that's just to the left of the address bar and turn off 'Enhanced tracking protection'.
Barsel: I'm using Slimjet, which is based around the same 'developer-level' browser (Chromium) that Chrome is, and I don't have the problem that you're seeing. However I think that more and more users of Chrome (and almost certainly all other major browsers too) will start to experience problems with websites that use third-party cookies (as AB does) in the very near future because Google is seeking to make them a thing of the past:
https://www.wired.co.uk/article/google-chrome-cookies-third-party-ads
Perhaps you've got a version of Chrome that's got the new feature enabled? (Browser updates are usually rolled out to users over a period of time, so some people will get an update before others do).