I have a stock RPi4 with latest RC1 (Also saw issue on Beta 5) and I cannot get Wired to connect automatically.
If I select the connection and "connect" it connects and works fine.
If I edit the connection, enable "Connect Automatically" and save, I go to check the setting and it is disabled again.
Am I missing something? This is a new RPi4 and has only had RC1 and Beta5 installed, both with same issue.
Thanks!