Dynamic workspaces are not working
I am on Gnome shell version 3.28.2 and have Dynamic Workspaces selected in the Tweak Tools options, yet have more than one empty workspace that is not automatically removed, up to the greyed-out number of static workspaces I would have if I had that option selected. When switching to and from static workspaces nothing happens.
I first noticed this because I had 12 workspaces open, 10 of which were empty. I then checked I had Dynamic Workspaces selected, which was. I selected Static Workspaces, which had the default option of 4 workspaces, then reselected Dynamic Workspaces. This pruned 8 of the empty workspaces only leaving 4 workspaces, 2 with programs and 2 empty.