Agentforce vibes extension in vscode keeps disappearing on every restart or sometimes without restart as well

The latest version of the Agentforce Vibes extension (v4.39.0) in VS Code keeps disappearing. To launch it, I had to disable/enable and reload the VS Code extensions; then it takes its own time to display the start page.  

How can I ensure the Agentforce Vibes extension remains visible at all times?  

Also, the chat keeps showing a 'loading models in progress' icon in the chat window, and even after waiting 30 minutes, nothing happens—so basically I can't use Agentforce in VS Code, as it works at random intervals and on its own.