Issue Poor Initial Server Response Time

[Daniel Richards]

Hi there,

I have a server with about 8 wordpress domains hosted on it. There's more than enough power for this. It was all going really well, However a few months ago, the initial server response time suddenly dropped for all domains (even just a initial basic wordpress with default theme and no plugins)

I've reviewed the instructions here: TTFB for site in Plesk is too high. What can be done to improve it?
and they haven't helped.

All sites are running PHP 7.4 and MariaDB 10.4


Gtmetrix and other tools confirm that the waiting is on the first initial server response, and not poor dns resolution.

Is anyone able to help me fault trace this?

 

[Bitpalast]

Put a phpinfo() Skript with just that very one command into the index.php file instead of your WP installation, then test again. Is the TTFB still high? If not, the problem is in Wordpress.