One server, two installs of the same php application, one works, the other super slow

I have a very strange problem.
One ispconfig server, I have two installs of the same php application. Both are the same version.
Both were working for a long time. Now one is super slow. So slow that I have to add php.ini configs to allow php to run longer and nginx to timeout much later.
These are checks done.

• both nginx configs the same
• both php-fpm 7.4 configs are the same
• did a mysql check on the databases and are ok

What else can I check?

Code:

php_admin_flag[display_errors] = on
php_admin_value[memory_limit] = 128M
php_admin_value[request_terminate_timeout] = 300

To make the slow one ‘work’ these are the settings used in php
the display errors are not showing anything on the webpage.

On nginx did the following config so that it will not timeout.

Code:

fastcgi_read_timeout 300s;

Debian 11
php-fpm 7.4
I would really appreciate some advice on how to find the problem or even fix it.
I just do not understand that both same php application are on the same server with the same php-fpm 7.4 and one is working but the other is super slow.

 

Tried restarting the whole debian server and the behaviour is the same.
the same super slow app is still the super slow app. :-(

 

Sounds like the perfect time to upgrade the php application to a PHP 8.4 or 8.5 compatible version.
PHP 7.4 has been EOL for over 2,5 years.

Maybe even upgrade the OS as Debian 11 will be EOL at the end of next month.

 

My bad for not updating.
The issue was solved in the forum of the application.
It seems that there was a link that checked for updates. That link is was not working and just php was waiting for the response and that made it super slow. The quick fix was to disable that function. Now all is good.
Yes I have set the php to be used to php8.3 for now.
The upgrade to Debian 12 is next but I am scared.
I know I will have to do it.