H4 Extn Application fee refunded

My H1B extension approved, however, my spouse H4 petition is still pending and on top of it, USCIS refunded the H4 visa fee without any request. Below is the update in the site.

On August 6, 2020, USCIS made the decision to refund the fee for your Form I-539, Application To Extend/Change Nonimmigrant Status, Receipt Number SRCXXXXXXXXX. Your refund will be mailed to the fee remitter on file. This refund does not affect the processing or location of your case

Did anyone aware about this situation?

You must have received an explanation letter with the fee refund. What does it say as the ‘reason’ for refund?

There is no explanation at all. Just mention of fee refund in the notice. Please see the attachment

This sounds strange as to why they have refunded the fee.

You should contact the Burlington USCIS office and ask for details. Or if you used an attorney to file this application, talk to them to see if they have received any correspondence from USCIS with respect to what has happened with your application.