The log shows the WiFi card is probed and bin/txt files are loaded (there are errors for device-specific files but it then falls back to the generic ones which is normal). So there is a wlan0 device, but there are lots of reference to tethering. Have you enabled tethering in LE settings?
NB: The "BCM4330B1.hcd" file needs to be in the same firmware/brcm/ directory for BT to work.
Yes, i was trying random solution and i enabled tethering.
Now i had some problem with ethernet adapter, so i reinstall again libreELEC ver. 11.0.0 and it works again, but still not wifi.
This is what dmesg.log write in a clean libreelec installation:
EDIT: finally i solved it!
The problem think was the missing "BCM4330B1.hcd" file, so i copy all three files in /storage/.config/firmware/brcm and reboot.
And magic! The wifi now works!
Thank you everybody for your support