так же в логах есть ошибка:
fpm_pctl_perform_idle_server_maintenance(), line 377: [pool www] seems busy (you may need to increase start_servers, or min/max_spare_servers)
fpm_pctl_perform_idle_server_maintenance(), line 377: [pool www] seems busy (you may need to increase start_servers, or min/max_spare_servers)