When an item sells out on Etsy we automatically set the stock to zero. If using stock by variation we will also remove all of the stock associated with each variation.
Here is how you can manually link an Etsy product to an existing IndieMade product.
Find the Etsy Listing ID
The Etsy Listing ID is included in the Etsy listing URL: https://www.etsy.com/listing/1346828509/tin-can-phones. It also shows on the Listings dashboard below the title
Replace the new Etsy Listing ID with the old Etsy Listing ID on IndieMade
Edit the product on IndieMade and expand the Etsy settings of the listing. Verify that the Etsy Listing ID is different and replace with the current Etsy Listing ID. Save the product. *Note that sometimes we all this the "Etsy Product ID"
Use the bulk editor to pull the new variations data from Etsy.
On the products dashboard select the checkbox next to the Indiemade product(s) and choose Update From Etsy.
In most cases choose "Pull Variations" as this is the most critical data as this is unique to each product. If you do not have variations pricing and stock should be automatically synced depening on your Etsy settings.