Hi Ethan, thank you, but I don't think the placeholders are indeed respecting the sizes I set. Look, these are the only sizes I allow for those placeholder:
On mobile and tablet:
Medium rectangle - 300x250
Half page - 300x600
On desktop
Billboard - 970x250
Large leader - 970x90
Also, I disables Adaptive sizing and Fluid sizes feature for them. But what you see in the desktop screenshot above shows that it clearly doesn't respect my settings. So what am I doing wrong here?
Regarding grey boxes and stickiness. I don't love it, but I'm willing to give it a go, as long as I have control over the sizes of the ads that are being displayed there. I need all ads shown there to always be of the same width: 300 for mobile and 970 for desktop. How can I achieve that?