Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
The APS Catalog has been deprecated and removed from all Plesk Obsidian versions. Applications already installed from the APS Catalog will continue working. However, Plesk will no longer provide support for APS applications.
Please be aware: with the Plesk Obsidian 18.0.78 release, the support for the ngx_pagespeed.so module will be deprecated and removed from the sw-nginx package.
I guess your issue will already be resolved.
However, if the others are facing this same problem, you can try to enable the apache status page by doing follow this link: How to enable the Apache mod_status module on a Plesk server , that may assists you locate the cause of the problem.
It's about your license. maybe license you are using is expired. Try to view panel log that located in /usr/local/psa/admin/logs/panel.log . (tail -f /usr/local/psa/admin/logs/panel.log)
I'm facing the same problem. Other website hosted loads normally and fast as lightning. But Plesk (17.5.3) is TOO SLOW! Maybe a bug? Any ideas to fix this problem?