Don’t pull your hair out … 😊

In more recent versions of Power BI, to change the display format of your measure in a card visual, do the following …

Click on the card visual. Then go the format pane (paintbrush), and the “Visual” tab within it.

Expand the “Callout” section.  Change the “Apply settings to” dropdown from “All” to the measure you want to change.

Scroll down, and change the “Display Units” parameter to your desired setting (“None” is also an option).

Optionally, if you do not already have the outcome you need from the above change, you can go to the “General” tab and make changes to the “Data format” parameters (such as decimal places, percentage, comma separator for thousands, etc) to get the exact number format that you want.

Good luck on your data journey!