Thanks for coming back for more support, @AmericanRV. The Undeposited Funds account in QuickBooks holds customer payments until they are deposited at your physical bank. 

Hence, you'll have to deposit it to your bank account first so it will show to combine these payments into a single record in QuickBooks to ensure that your bank records are matched.

Check out this link for additional insights about how the Undeposited Funds account works in QuickBooks Desktop. 

Feel free to message again if you have additional concerns about posting refund checks. Take care!