TAB shortcut broken

The only workaround I've found so far is to create a new workspace with a large Preview panel and nothing else except the Tool Bar at the top and either a small 'Content' or 'Filmstrip' panel.

This works but apparently the shortcuts to switch between workspaces are broken. They're supposed to be ALT-SHIFT-1 through 5 but that doesn't work. Tech support says that this is a known issue with no fix.

This is such basic functionality and absolutely crucial. Why did they remove it????

This has been a classic feature in Bridge, and is very crucial for sequencing or comparing images. It's weird to take it away. Used to be able to show maximum of 9 photos, and that could be ramped up to say 20.