Community
If you are part of more than one Fusion360 "Hub" then you need to pay attention to where you create and save your projects. Recently I created a new project, went back the next day and couldn't find it. Turns out I had saved it in a different Hub and next time I opened Fusion I was looking at my main page.
Finding the Hubs that you belong to is easy: in the main dashboard, go to the upper right corner. Use the drop down tab with your name on it. This will show you the list of Hubs. The active Hub will always be at the top of the list.
Great guidance!