At Mediavine, we lazy load our ads, which means you have to be careful with any lazy loading you do on the page to make sure you're not doubling up on your lazy loading. Doing so could potentially break your ads.
You will need to check your settings and configuration options to make sure you only lazy load images.
In the popular WP Rocket plugin, you want the following settings, making sure only "Enable for images" is checked and NOT "Enable for iframes and videos":
Lightspeed Cache for Wordpress
Lightspeed has a separate toggle for "Lazy Load Images." Make sure you enable that one and do NOT enable "Lazy Load iframes" and you should not impact your ads.
Enabling Lazy Loading is a major change to your site and something you are doing at your own risk.