Created attachment 851456 [details]
NetworkManager logs, inxi-Fxz output, video and photo with error demonstration

After installation, the wired connection works correctly. The next day, it
stops connecting. There is a network connection that lasts indefinitely.
Creating new connections does not lead to any result, as does trying to
reconnect to an existing connection. It only helps to roll back the system to
the backup created immediately after installation. The bug manifests itself on
all DE and the next day after installation. During installation, the system
configures the wired connection itself and the installation takes place without
any errors. The problem manifests itself in openSUSE Leap and Tumbleweed, the
wired connection works correctly on other distributions. I tried to install the
r8168 driver, and add r8169 to the blacklist, but this does not help.
Installing a third-party custom kernel also does not fix the problem. IPv4,
IPv6, DNS and the default route disappear from the connection settings. I
looked at the Network Manager configs, but there is nothing suspicious there,
because of which the problem could manifest itself.