The only extension I have is LastPass. I can’t imagine that is side loading any ads.
I tried visiting in a private window and it does indeed get rid of the ads like the normal view should and used too. A screenshot of that is included below:
However, I do a get a wide range of behavior where it will load legit assets sometimes and others times not. Some examples are included below:
I’m not sure what another “brave profile” means, but I have tried this on another Mac running macOS High Sierra 10.13.6 where it still shows the ads. I also tried it on a Windows 10 machine where it was a fresh install of Brave. It doesn’t show the ads there, but it does still bring in the banner ad you can see in the screenshot below from the Mac machine running macOS Mojave 10.14.6. I don’t have a good way of getting a screenshot off of the Windows machine.
Interestingly, if I log out of my IMDb account, then it blocks the ads. It still it brings in the banner ad before taking it out, but it’s back to the way it was before even when I was logged it in except it’s still turning the background black for some reason.
If I log back out again, it seems to fix it. At this point, I’m stumped. My best guess is that Brave is being thrown off a bit because it looks like they are trying to intermix Amazon with IMDb more in order to push Amazon Prime and they are in process of migrating the site over to a new look.