While I wanted to get back on the stable track until next June, bit the bullet and upgraded to the 12.1 beta in hopes that would fix this Network panel issue. Thankfully it does. Upgraded and now Network Preferences properly shows the ethernet as green/connected. For those on the stable version, perhaps someone will have a workaround to suggest here in the meantime.
Topic:
App & System Services
SubTopic:
Hardware
Tags: