you might've been revoked for a unknown reason.
No, if your key is revoked then authentication will fail on the main menu. It won't ever say "Welcome, <your name>"
The cause of this is most likely that your UDP and TCP traffic are being routed differently. So you end up authenticating with one IP address, then connecting to servers with a different IP address. Common causes of this include using a proxy or other anonymization tactic, or connecting via satellite or cellular network.
This will also happen if someone else uses your key or if you start another instance of Blockland and change your name. Looking at the master server, this doesn't seem to be the case for you.