TAGS NOT BEING SAVED IN TRIGGERS
Using Custom CSS Tag Issue
Go to > Settings > Company > Scroll down to the Custom CSS Dashboard. Once in the dashboard, look for the Hide Tags and delete that line in the CSS. You can use ctrl-f to search for it.
When adding a tag in your Triggers, It won't let you save it even when you click add action.
It is unnecessary to add tags since there is already a built-in function. An example would be in this Opportunities tab, where you can toggle the hide tags on or off.