If you've recently switched from Classic Editor to the Gutenberg Block Editor, you may have noticed that your Create cards are now showing up as shortcode in the post editor.
This can happen with any shortcode based plugin when you switch a post from Classic to Block Editor; it's not exclusive to Create.
Check to make sure the card is still showing on the live site. It is possible that you may just see the shortcode displayed on the front end as well. If the card is missing in the live post, remove the shortcode and add the card to the post once more. If the card is still there, no action is required.
Even if the card is in place on the live site, you can still remove the shortcode and add the card back into the post, so you can see the card thumbnail in the editor as normal.
Alternatively, what you see in the editor may look something like below, meaning the shortcode is not populating correctly:
You will want to click Attempt Block Recovery to add the card back in to the post or simply delete the shortcode and insert your card again.