The team workview does not display correctly when acting for another worker, switching to narrow view and then acting as the logged in worker.
To replicate this, follow the steps below:
Log in to Mosaic and you're presented with the Full workview layout.
Act for another worker.
Go to Narrow Workview - Act for another worker.
Click Team View.
This has been confirmed as a bug and will be fixed in a future Mosaic version.