When you open a view from the view map, it will open with the settings as saved in that view and the tab should not have an (!).
If you now manually change any of those settings (layer, scale, graphic override, etc), then the tab name will now have a (!) to indicate that something is not the same as the original view settings.
Double clicking the tab name will reset the default settings for that view.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10