First time selling - buyer claims the wrong address was provided - is this legit?

Do NOT ship to a different address than the one specified in the transaction. If the buyer made a mistake in their address, tell them you must cancel the sale, and they can fix their address and purchase the item again.

Don't change the address as you will lose sellers protection.

If you "know" that ebay is notorious for siding with the buyers, you should "know" that you don't change the address. BTW, if you follow the rules, and call ebay when there is an issue, you will rarely lose a case.

Get the buyer to change the address on their side. If they cant/won't you will have to cancel the order and use the reason as problem with address. Then relist.

More info on address scam.
THIS FROM PAYPAL :
Package rerouting scam
• The buyer reroutes the package so they can file a complaint that they never received it.
• A buyer places an order and provides an incorrect or fake shipping address.
• The shipping company tries to deliver the package but isn't able to.
• The buyer monitors the online tracking information and notices that the shipper couldn't deliver the package.
• The buyer contacts your shipping company and asks them to send the package to their correct address.
• The shipping company delivers the package to the new location.
• Buyer then files a complaint for not receiving the item.
• Because the shipment was rerouted, you can't prove the item was delivered to the address on the Transaction Details page.
• The buyer gets to keep the item and money.
• Because the package wasn't delivered to the address on the Transaction Details page, you aren't covered by Seller Protection.
Unfortunately, you lost the product, shipping fees and the money.
To make it worse, you might also have to pay your shipper an additional rerouting fee.

How to avoid this scam:
• Contact your shipping company and block buyers from rerouting packages.
• Validate the buyer's address before shipping.