After two years, suddenly connman WiFi scan ceased to work and I'll write this post to help anyone who will face this bug in future
I don't often use WiFi, so i don't know with precision when this happened, but it was after January (the lat time i used WiFi on my notebook) so i don't know either what update was the culprit.
Investigating leads me to the arch forum wiki (https://wiki.archlinux.org/title/ConnMan#Error_/net/connman/technology/wifi:_No_carrier) .
I saw some posts also here on the Artix forum suggesting substituting connman with network manager as only solution to the problem.
I don't want leave connman so i try deepen the question, without luck..... It seems there is no way to solve this problem.
As last resource i try to launch connmand from cli, and it threw this error:
error fi.w1.wpa_supplicant1.UnknownError
wpa_supplicant works well for me so the problem is in connman wpa_supplicant interface.
So instead to substitute connman with NM i switched wpa_supplicant for iwd.
In Artix it is as simple as remove all wpa_supplicant related packages and install iwd and iwd-your_preferred_init.
Obviously change "your_preferred_init" with the init system you are using ;)
Now connman works flawlessly, again.
I rarely use wi-fi either, but I don't need the connman or the NM for that.
RTFM:
https://wiki.archlinux.org/title/Wpa_supplicant
https://wiki.gentoo.org/wiki/Wpa_supplicant#Configuration
https://wiki.gentoo.org/wiki/Wpa_supplicant#Usage