I recently upgraded to GS 8 due to the fact that GS 7 would not update ebay store categories and shipping preferences and worse off it kept crashing on me. Now that its updated it continues to crash and still no categories or preferences. I tried refreshing the token and all it does is logs into ebay and doesnt refresh.
What you describe might be an issue with your eBay token.
Removing your eBay account from the GarageSale preferences > Accounts, restarting your Mac and then re-adding your eBay account might fix it BUT there’s currently an issue with eBay’s authorisation flow so you won’t be able to fetch a new token at the moment.