Whenever I click on an Etsy ad on Facebook to consider a product made by another Etsy seller the link only opens in my seller app. There is no way to click a FB ad for another Etsy shop and actually get to the item clicked on. Etsy and Etsy sellers have definitely missed out on sales (to me at least) due to this glitch. I wonder if my own shop has missed out on sales or exposure for this reason, too. It would make so much more sense if clicking on a product in a FB Etsy ad linked you to the product in the shop in your browser.
FYI using an iPhone.
You will need to contact Facebook since that's where the problem is.
@SpinningWheelStudio: I believe that Apple has made it so that the default setting is for a link to open in the corresponding app and you probably need to change the settings on your phone.