The Linksys Velop system typically displays this error when it is unable to establish an internet connection or fully sync with the main node. Make sure your modem is turned on, your wires are firmly in place, and the Linksys app is up to date in order to resolve the issue. Try setting up again after restarting the Velop system. Common Linksys issue 2123 can frequently be fixed with a... https://velosetup.com/getting-linksys-error-2123-during-router-login-lets-fix/