- Plesk Onyx for Linux
The PHP handler is changed from FastCGI to PHP-FPM served by nginx in Domains > example.com > PHP Settings after migration between Plesk servers.
It is Plesk Migrator bug PMT-2344, which will be fixed in future product updates.
Currently there is no workaround available.
Change the PHP handler back to FastCGI in Domains > example.com > PHP Settings manually.