Your card design will save automatically each time you make a change, and will save one more time when you navigate away from - or close - the Customize page.
Please note that if you have your customize page open in multiple browser tabs or windows, it's possible that an older version of your card design will be saved over the most recent version when you close the older tabs/windows. Therefore, we highly recommend working in only one tab or window at a time.
If your card says "Saving" but your updates don't save, please contact our Support team.