Can I return to my Q chat history after re-logging in, without asking a trivial question?

It seems you CAN avoid asking a dummy question from the first welcome screen after re-authenticating:

1. Use the vertical ... menu in the top right, beside the '>' hide panel icon below the 'Q' icon, to select 'welcome screen' (even though you're already on it)
2. On this new welcome screen, click the 'x' to the right of 'Hello! I'm Amazon Q, your AWS generative AI assistant.'

The conversations appeared immediately for me when this second welcome screen was dismissed, and were subsequently available from the top left vertical .-.-.- menu button.

Less of a nuisance than typing a dummy prompt, but still an odd flaw.

Based on the available information, Amazon Q Developer now offers conversation persistence features, but the specific behavior you're describing in the AWS console environment appears to be different.

In the AWS console environment, Amazon Q generally does not provide access to older conversations from previous sessions. When your SSO times out and you have to log back in, the system treats this as a new session, which is why you're seeing the welcome screen rather than your previous conversation.

The conversation persistence features that have been recently added to Amazon Q Developer are primarily available in:

1. Visual Studio Code extension - where you can access previous conversations by clicking on the search icon in the top right corner of the chat window

2. Amazon Q Developer CLI - where conversations are automatically saved by working directory, and you can use commands like q chat --resume to pick up where you left off

For the AWS console environment specifically, it appears that you currently need to initiate a new conversation (by asking that "trivial question") before you can access the hamburger menu that lets you see previous chats. This seems to be a limitation of the current implementation in the console environment, as Amazon Q in the AWS console is designed to focus on current, active conversations rather than providing immediate access to a historical log of past discussions.

If this workflow is disruptive to your experience, you might consider using Amazon Q Developer in VS Code or through the CLI where the conversation persistence features are more robust.
Sources
Continue to take control over your code with Amazon Q Developer’s new context features | AWS DevOps & Developer Productivity Blog
Exploring the latest features of the Amazon Q Developer CLI | AWS DevOps & Developer Productivity Blog
Q discussions in AWS console environment | AWS re:Post
Conversation persistence - Amazon Q Developer