Recently, I noticed that it took a long time to sign in to the Plesk interface. I used to sign in within a second; now, it took anywhere from 30 seconds to 2 minutes. After a successful login, everything seemed to work out fine; you could check this and that without a problem. Navigating between the domain/website pages had a similar situation; the status on the top just ran and stopped and waited for a minute before displaying all the domains detail. This problem only exists within the Plesk interface, and all websites are showing reasonably fast using any browser.
Some folks on the net suggest that that could be a problem with the sentry.io tracking. After all, when you log in, the bottom status bar suggests that the system tries to connect to sentry.io of some sort. Some experts suggest adding the lines [feedback] sentry.dsn = “” to the file /usr/local/psa/admin/conf/panel.ini will solve this issue. If you don’t like to use shell access to edit the file, there is a Plesk extension that allows you to edit that file easily. I tried, but that problem remains. Many online experts suggest that detailed investigation, such as checking all sorts of log files, is required to pin down this particular slow login problem.
Then I found a help page from Websavers, “This has been reported to occur when certain Plesk extensions are installed. The worst offender so far has been the SEO Toolkit extension, presumably as it loads data when viewing a particular subscription or domain.”
Oh wow, so I disabled the SEO Toolkit extension, and things are back to normal; there is no more slow login.