The cause of this is a live news section provided by WP Bakery features that contains img tags with no height or width attributes. This section is not present on the second site, which is why it does not have the CLS issue the other 2 have.
I have developed WP theme for 3 webisites. Both are using pure WP codex code. No frameworks, nothing. The only thing I use is WP bakery PB plugin. But still it is not passing the CLS. I am switching the theme to Twentytwenty or any other default WP theme, turning of all the plugins, but still CLS is going MAD!
This is a contradiction, you are using a framework, it’s called WP Bakery PB. This on its own contributes enormously to your layout shift problem. For help with that, contact WP Bakery support, 3rd party product support questions are off topic here.
For that reason I bought a VPS 12 cores, 16gb RAM. Running CentOS -> CyberPanel with Open Light Speed server, using LS cache, page loading on hover. Nothing helps. Visually the page load is like “light speed” but not for G guy.
Layout shift has nothing to do with how fast your server is, it’s a browser metric, not a server metric. Making your server faster will change nothing for cumulative layout shift.
The websites almost identical(i mean content but the code and plugins are the same with same versions), but the thing is that on the website number 2 the CLS issue doesn’t exist.
Because CLS is not about server side code, it’s about frontend performance in the browser. The content and HTML+assets that get sent are what matters.
WP promised on v6.0 to fix the CLS issue, but by then what plugin or code I can use to disable something on WP core to run it faster for the G?
No, it did not, and this is not something that WP can fix because that’s not how this works. There is no plugin or code, and there is nothing to disable in WP core.
It’s clear from this that cumulative layout shift doesn’t meant what you think it means. CLS is when things change height or width as they load, forcing the browser to redo the layout of the page slowing down the browser. It isn’t because your server is slow, or because WordPress core didn’t fix a bug.
CLS is when you forget to put height/width on an image tag, and it has no height, then it loads in and shifts everything around to make space. That’s what CLS is, the pushing stuff down part, recalculating the layout slows down the browser on your computer, and that’s what Google is complaining about.
There are lots of causes of CLS, but those are all generic HTML/CSS/JS issues, and they’re the responsibility of plugins and themes not WordPress itself.
Further Reading: