We seem to face an issue on our all servers, the problem seems to be that the website requires few sec to load every single page, and that's not good for our clients eshop website (image attached). Few notes to avoid losing time:
1. All websites are using WP
2. CDN Caches is used (StackPath)
3. DB optimised (WP Rocket will not solve the issue even the paid version)
4. N0 images are actually saved on the server (all are based on links)
CentOS Linux 7.9.2009 (Core)
FPM application served by Apache
I do believe it's sth related to the server, but that's my opinion, so; we need someone with good expertise to find and solve the issue.