I just tried it but nothing happens when I click on that. You're talking about the thing on the upper left next to the open/close menu button?

Yes, very frustrating for me as well. I consider now purchasing Gemini Advance with another Non-Workspace account. :-(

I also found this [1]: “ Important:

A chat can only use one model. If you switch between models in an existing chat, it automatically starts a new chat. If you’re using Gemini Apps with a work or school Google Account, you can’t switch between models. Learn more about using Gemini Apps with a work or school account.”

I have no idea why the workspace accounts are such restricted.

[1] https://support.google.com/gemini/answer/14517446?hl=en&co=G...