GTM quirk #17: beware the ‘!’
DataStudio quirk #15: adding segments to blended data
In CSS, using the ‘!’ in Class or Id names is not recommended. Technically it’s an invalid character, and certainly in Google Tag Manager your Triggers based on any CSS element that includes a ‘!’ in its name will not work. You’ll need to escape the ! (‘\!’) to get the trigger to fire.
If you decide to update a scorecard (for example) by adding a segment to a data source, you’ll also need to edit any blends that refer to that scorecard – in other words, blended charts don’t inherit changes to their source data.