There are a few possible reasons why you may be unable to connect to the RDP server at "my.server.ip" using Remmina in the latest version of Ubuntu:
1. Incorrect configuration: Double-check the server address, username, password, and other settings in Remmina to ensure they are correct. Make sure you are using the correct protocol (RDP) and port number.
2. Firewall or network issues: Make sure there are no firewall restrictions or network issues preventing the connection to the RDP server. Check with your network administrator to ensure that the necessary ports for RDP are open.
3. Remmina settings: Check for any specific settings in Remmina that may be causing the connection issue. Try resetting Remmina to default settings and retry the connection.
4. Software or compatibility issues: Ensure that both Remmina and Ubuntu are up to date with the latest software updates. Check for any known bugs or compatibility issues with the version of Remmina you are using.
If you are able to successfully connect to the server using the terminal, it may indicate that the issue lies with the configuration or settings in Remmina. Try troubleshooting the above possibilities and see if it resolves the connection issue.