I’ve also sold things to US and pre-paid tariffs to my shipping broker.

I’m doubting myself or my buyer will be getting a refund.

Same for my buyer that bought items via eBay, paying the tariffs, through the EIS/eBay International Shipping service where the buyer pays for it and I ship the item to eBay in Canada whom trucks it over the border.

It may be doubtful, but it seems like it would be worth looking into to see if you qualify for a refund?