When the checkbox "standby connesso invece della sospensione" is selected, the pc does not go in any way in suspend mode, even if on battery power.
De-selecting the checkbox, the pc can suspend right.
When checkbox is selected, the result is that if you try to suspend in any way from E (closing the lid, via system button "suspend") the system reduce backlight but stay on, and the only way to come back from this strange state is pressing the power button, that open the panel to shutdown your pc, or with ctrl+alt+f[1-6] open a new console to restart lightdm.
Linux debian-paolo 4.19.0-1-amd64 #1 SMP Debian 4.19.12-1 (2018-12-22) x86_64 GNU/Linux
enlightenment version installed:
enlightenment/testing,unstable,now 0.22.4-1 amd64 [installato]