Once you have changed the name refresh your eBay access token in the GarageSale preferences > Accounts and also click the “Update Account Details” button.
Well, I changed the name of my store. Or at least eBay recognizes that I did that.
But GarageSale apparently doesn’t know about it.
I’ve clicked on the "Update Account Details” button a few times since I made the change yesterday. I’ve also clicked on the more annoying “Refresh Access Token.”
I guess it might need some time until your new store name is available through the eBay API. Not sure how long it takes - maybe you wait 24h and then give it another try?
I tried it here, renamed the eBay store, clicked on “Update account details” and reloaded the Preview. The new store name showed up immediately in the Pro Design. So my guess is that it should work for you, too.
What happens if you create a new listing from scratch and select a Pro Design and a store category? Does it still display the old store name?