kodi won’t fire up setwakeup.sh

Hello, sorry for my bad english, i’ll try to do my better to explain my problem.

I tried to build my own kodi system. I tried both with OpenELEC and LibreELEC, all goes well, but i have a problem with pvr recordings (i use tvheadend backend) on both of them:

if i program a record from the epg screen, it is correctly flagged as programmed record, for example, i try to program a show which starts 4 hours in the future (over 15 minutes in settings), then if i turn off my htpc, i expect that the setwakeup.sh script is fired up and the rtc updated to boot few minutes before the show starts (all as settings in the proper config screen). However this does not happen. Looking at logs i can read this error:

Code:
17:08:09.451 T:140157520614336   DEBUG: CSettingsManager: requested setting (pvrpowermanagement.enabled) was not found.
17:08:09.452 T:140157520614336  NOTICE: PVRManager - stopping
17:08:09.558 T:140156115101440   DEBUG: Thread PVRManager 140156115101440 terminating
17:08:09.568 T:140157520614336   DEBUG: PVR - Destroy - destroying PVR add-on 'Tvheadend:127.0.0.1:9982'
17:08:09.950 T:140157520614336   DEBUG: SECTION:UnloadDll(/storage/.kodi/addons/pvr.hts/pvr.hts.so.3.4.18)
17:08:09.950 T:140157520614336    INFO: ADDON: Dll Destroyed - Tvheadend HTSP Client
17:08:09.950 T:140157520614336   DEBUG: CSettingsManager: requested setting (epg.daystodisplay) was not found.

and setwakeup.sh is never fired.

Searching in this forum i found a very old post (related to kodi 12.2) without answers, so i hope some kodi team member can find the time to point me in the right direction to understand the problem