If your clients are having issues seeing the CVV or credit card box when authorizing credit card charges it may be due to a Javascript error on the device they're using. This is most common on iOS using the Safari browser.
To fix this, have your client access Tern on a different browser of device. Switching to a desktop or laptop generally solves the issue.
We also ask that you notify the Tern team of the issue including:
The date/time it happened
What device the clients were using
What browser the clients were using
This will help us track down the root cause of the issue.