Try restarting your modem and Velop nodes first. Verify your internet connection and make sure the firmware on your Velop has been updated via the Linksys App if the issue continues. Linksys support offers specialized tools to help fix this particular issue and restore your mesh network's functionality if you need more help. https://velosetup.com/getting-linksys-error-2123-during-router-login-lets-fix/