USPS tracking shows item going to Mail Recovery

I shipped an item from Iowa to Hawaii. Shipped March 17. Out for delivery March 30 610am. At 900pm tracking showed: Awaiting Delivery. And that's it nothing else. I waited for the buyer to contact me as I've understood sometimes they could have received the package.

Buyer opened INR case last Thursday.

I wish they would have sent me a message first!!

I Immediately opened a missing package case with USPS. I found another avenue to contact USPS regarding this: Email Us Domestic Tracking and shipping. I cant get any further on that process because it says:

This item is on its way to or has arrived at our Mail Recovery Center. Please visit https://faq.usps.com/s/article/Missing-Mail-The-Basics to learn more and submit a Missing Mail search request.

I've had communication with the buyer thru the open INR case. They keep saying they will "wait another week before they request a refund and leave neutral feedback."

I dont have a week after INR is opened. I dont want EBAY to force the refund. I have no issues sending a refund but what if this package shows up? I know I can claim with USPS but I am at a loss working with this buyer as I don't think they comprehend how opening a case affects seller performance, etc.

I've never had this issue and the item is about $50 including shipping.

Any advice?? Based on the info that this is going to or at the mail recovery center, I understand this can take a while to sort out. Do I just refund the buyer and wait on the missing item search and hope it will get sent back to me or file a claim with USPS? I am really trying not to have my seller performance affected...especially when fault lies with USPS.