I have an install with site wide bad LCP:
https://pagespeed.web.dev/
https://www.touruno.com/
Google webmaster tools notification:
error_outline
100% of your pages load slowly (LCP)
Faster loading generally improves user experience. Consider reviewing affected pages to see if improvements can be made. Learn more about the Core Web Vitals report.
I'm using CloudFlare and jch-optimizer with no luck.
Help is appreciated.