When I open my website on desktop mode, first the main content area loads, and then the right sidebar area loads. Due to this, the advertisements get stretched to the right side. Once the page is refreshed the ads come to the correct position.
We use Advanced Ads to insert the ads. And WP Rocket as an optimization plugin. Yes, the problem is resolved after disabling the WP rocket. But I don’t understand what settings in WP Rocket cause this.
I see. Try temporarily disabling all settings of WP Rocket and activating them one by one. Usual culprits are any form of minification/combination or merging of CSS and JSS.