Slow browsing after server migration

[isness]

My hosting provider forcibly moved my site to another server, and now browsing through directories in Encode Explorer is painfully slow. It takes more than 4 seconds after the intial GET request to receive anything. And it's the same with every directory, as well as loading the login screen. I'm guessing a number of things are different in the new server, including PHP version and perhaps some of the settings. I'm not really sure what changed because the old server is available no more. Other than that, no new files were uploaded or directories created. The number of files is fairly large, and they take up 32 GB. The log is file is also large, about 60 MB. Yet these things were not an issue on the old server.

All PHP settings are visible on https://pasiflora.serveriai.lt/PHP/

Any suggestions on where to start debugging? I'm not really much into PHP.