Make sure you have no other token gating apps installed that inject Wallet Connect code onto your theme. If you have any of these apps installed you may have to uninstall them

If you are using a custom domain (i.e. your shop URL does not contain .myshopify.com) -> Go to the Welcome tab of the Manifold Merch Bridge App and make sure you have entered in a Wallet Connect Project ID. If you do not have one you can create one here