In compliance with industry standards, a recent change was made to eliminate the practice of processing an initial $1 authorization and a subsequent authorization and capture for the full amount for online transactions made through Sphere. 
One consequence of this change, however, will be an increase in debit or credit card holds if the transaction fails, as the authorization and capture of funds is now for the full amount.  The hold periods can vary by card type or issuing bank.  This is standard card industry practice.  When a credit card is processed it goes through several verification levels depending on the organization's verification settings for credit cards, such as expiration date, Address and/or Zip Code.  The last verification is CVV, which is required.  It is the bank’s responsibility to reject any transactions submitted without the correct CVV for security purposes if it was required at the point of entry.  This is why the transaction appears to be accepted at one point and then credit back to the donor’s account. 

To help avoid this in the future:
It is recommended that your online transaction sites be designed to recognize the importance of entering the correct card information, i.e., billing address, card expiration date and CVV information when submitting online donations.  

If you have any additional questions or concerns regarding this information, please create a case: Chat with Support and reference this article.