Yes, you should cancel and refund with “problem with buyer’s address”.
You’re relatively inexperienced as a seller; I would strongly suggest you go into your settings to exclude international buyers. For expensive items in particular, there is a substantial risk.
You should change both your postage settings to exclude international postage, and set your buyer requirements to exclude international eBayers from bidding on or buying your items.
❝How to prevent international buyers from purchasing your items
Given the nature of eBay's global marketplace, eBay listings may be viewed and purchased by, and posted to, buyers around the world. Such listings may be shown on the same or a different site on which the seller listed the item, based on the seller's postage settings. If you do not want your item to be sold to buyers internationally, you can exclude countries or regions you don't want to post to by adjusting your postage settings. If your item sells, you will be bound by the User Agreement and policies, including any buyer protection policies, of the site on which the item is sold and, potentially, the laws of the country of the relevant site. Buyers affected by your requirements may still see your listings, but they won't be able to bid on or buy your items.
To exclude international postage for all your listings:
- Go to Manage postage settings.
- Next to Exclude postage locations, select Edit.
- Select the boxes for all the countries and regions you want to exclude.
- If you want these settings to apply to your current active listings as well as future listings, select the box Also apply to current listings.
- Select Save.
Setting buyer requirements: You can also set your preferences by setting buyer requirements. These preferences will be used as the default for all of your future listings, and, if you use the new listing tool, you can make listing-specific changes to them at the time of listing.
Individual listings: If you sell using the new listing tool, you can exclude or include international postage for individual listings.
When you create your listing, in the Postage section, adjust your international postage preferences and excluded countries list as appropriate:
- In the International postage subsection, select No international postage from the drop-down list, or
- In the Exclude postage locations subsection, select Create exclusion list to indicate countries/regions to which you do not want to post.❞
https://www.ebay.com.au/help/policies/selling-policies/international-selling-policy?id=4689
