When you join Ledger and create a team, or if you've been invited into an existing team, each will also have their own dedicated workspace. That means that each will have its own dashboard, and every section, like streams and projects, will be specific to that team (workspace). This is done to keep all of your teamwork inside each workspace more aligned and less confusing.
You can toggle between these workspaces by clicking the workspace icon in the left navigation bar, or inside the mobile drop down navigation menu.
Note: chats, bookmarks, reports, settings and notifications will always be universal. That means regardless of the workspace you're in, you can access all of these sections (such as your chats or bookmarks) without needing to toggle between workspaces. Keep in mind that if you click on a bookmark or notification in a different workspace than the one you're currently in, your current workspace will update to the one selected.