Why suddenly the network interfaces of my device changes the state to DOWN and even If the link is connected is impossible to change it to UP.
Also, sometimes, Wi-Fi interface disappears and It is impossible to re enable. In this case the interface disappears and only is solved unplugging the power supply, If I do a reboot, the system crashes.
This suggests that some piece of hardware is failing. The link can only be brought UP if the cable is connected AND both endpoints are “link trained” - in other words, they are both electrically ready to communicate. I would check your switch and inspect the link status lights, the output of ethtool for the interface, and the system logs.
Is this a different interface than the “ethernet” interface you talked about in the first paragraph? Start with inspecting your system logs. It looks like hardware failures from a quick glance.
As a probe/error check, if I connect to other device its state is UP and communication is successful. When i plug it into the device with Clear Linux it is sitll down and not working. So the switch is working well. I also inspect the logs, and I don’t found any clear issue.
Yes, this is another interface. No hardware failure appears. The system does not detect it anymore.