No way to get network work in a Pi 3B+

[marciano1]

motionEyeOS version: motioneyeos-raspberrypi3-20200606.img
Raspberry PI 3B+).
NoIR camera, extra IR light.
My motionEyeOS unit is connected to the network via: WiFi, Ethernet.

From Ubuntu and Raspberry Pi Imager v1.7.2 (also tried with Balena Etcher) I wrote a microSD card.
Boot from Rpi 3B+ doesn't get network connection, checked with sudo nmap -sn 192.168.1.0/24
So I tried an alternative from Wiki
sudo sh writeimage.sh -d /dev/sdf -i "path-to/motioneyeos-raspberrypi3-20200606.img" -s "192.168.1.104/24:192.168.1.251:8.8.8.8"
(static IP, Gateway, DNS)

No way to get it work, no IP available. Tried changing the RJ and power cables.
Network is okay in this rPI with other OS like Bookworm.
The strange thing to me is that turning on rPi with motionEye green led on board continuously flashes slowly 4 times and then rapidly 7 times.

I have another motionEyeOS in a Pi 4 and both Ethernet and WiFi are discoverable.
I don't get what else to try.