I'm so sorry this happened. As NanaLetha shared, Etsy will not change the review. If the buyer can't or won't change it, it's not a real worry even though it is a temporary problem. One poor review will not hurt a shop. And the buyer still may reverse the review. But it would be best not to send them multiple requests to do so as it could cause frustration. They may have tried to do so and had issues with their operating system or an app. Some people are not savvy with their phones or computers. What's most important is you have a happy customer which is obviously the case.
Most sellers who have achieved the Star Seller badge will float in and out of it at some point. I've lost it for hand delivering items per a customers request and 4 star positive reviews. And I've gained it back at times too. It has made absolutely no difference with my traffic or sales nor how I run my shop. However, if the majority of a shops reviews are poor then that will impact the shop within search. But again, that's simply not the case here. I hope sharing this helps.
