ERR_NETWORK_CHANGED every couple of seconds on new KDE installation

I have new KDE installation and I’m having network issues. Every couple of seconds I get ERR_NETWORK_CHANGED error when browsing or working with API’s. I’m using wired connection, other devices work fine.

Either you run dhcpcd or NetworkManager service, but make sure you do not run them both …

NetworkManager is running, dhcpcd is not. I’ve read somewhere that there is a problem with network if you use Docker. I’ve disabled ip6 as this was one of the proposed solutions. I don’t get ERR_NETWORK_CHANGED anymore, but now every couple of seconds I get that notification that says Wired Connection X deactivated. Wired Connection Y activated. I can live with that for now.