I am using an ad blocker and EFF's privacy Badger to lock third party cookies too, but advertisers and site owners are finding every day more and more egregious ways tho shovel to you useless ****.
As you can see in the screenshot, the modal pop up is internally generated by the site itself, and points to an internal page of the diabetes.co.uk site.
This is really annoying. Especially if one had already done the thing ant there is a red banner on the top of the page.
By the way the simple html is 41 kbytes the total downloaded data goes to a whopping 3884 kbytes. If one has a low speed connection