Can't switch back on via WOL after power off

[chunky]

hello there

I've an issue where if I power off opnsense machine with web gui or via the api, I can't switch it back on remotely with WAKE ON LAN packet. The hardware is capable and the bios is setup to switch on by WOL. Tested Windows and linux on the same machine, WOL works ok after regular power off.
As a side note, if (instead of powering it off) I put it to S3 sleep, it wake up nicely via WOL.
Unfortunately, acpi sleep (tested with command: acpiconf -s 3) is not available via the api, only poweroff is. May be it could be possible to add this option (s3sleep) in the api ? Can anyone could tell me how to do this ?

opnsense 18.7.6-amd64 on a zotac nano CI321