It’s not installed at the moment. It’s a production environment so I rather not mess with it too much. Please test it locally instead.
Anyway, the cart links plugin isn’t the issue here. I purchased the extended coupon plugin and it seems to not work with add-to-cart so I can’t use it. I’m not really interested in workarounds as I need it to work with add-to-cart.
I read another thread from someone using add-to-cart with the the extended coupon plugin and having issues too. Add-to-cart is commonly used so I really think your plugin should support it or state that it doesn’t support it.