Rock Pi 4B + Ubuntu + Wi-Fi/Ethernet

I have problem configuring at the same time Wi-Fi and Ethernet.
While Wi-Fi is working without problem both ways, Ethernet at the same time cannot be started and even if random things happen and Ethernet has IPv4 - I cannot connect to it from PC.

Is someone else observing such problem?

Ok, got it!

Both eth0 and wlan0 can’t work in the same time on this OS.