CLS increases

It is clear what is happennig. A videoframe doesn’t hold the place for itself and shifts the content down after having been loaded. The question is why it behaves like this.

If we take a post without any video, then we notice a place for a picture.

https://sorokanews.ru/2021/02/06/raskryta-vozmozhnaya-prichina-smerti-vitaliya-alshanskogo/

Well, that’s not how LYTE is _supposed_ to work (the code explicitly sets a grey placeholder in plain old HTML) and it was not visible in the webpagetest 60FPS capture of your page loading I shared earlier.

Maybe something specific to your site (theme/ plugin) is meddling here somehow? But as I wrote; I have no idea what is happening here and as much as I’d like to I cannot help you :-/

I gave two different sites with different themes, and the problem is the same. The thing is in the WP Lyte plugin. It much helped with mobile version but desktop one suffers a lot.

Pretty sure desktop performance would be way worse without LYTE, even if CLS is higher in your case ??