Customers sometimes blocked from selecting country at checkout

1 0 0

I have had a few customers reach out to say they are not able to select a country at checkout. The box is empty so nothing can be selected. It also happened to our CEO when she was placing her order on the weekend except she was using ShopPay and got the error "shipping is not available for the selected address" since her address was pre-populated.

This is happening intermittently and when I have gone to test it seems to be working fine. When it does happen it is blocking our customers from checking out and completing their purchase so its super important for us to understand why!

Additional info: We only do local delivery and pick up but are not using Shopify's local delivery app. We use Zapiet's Store PickUp and Delivery app so customers can choose their delivery date and time before they get to checkout. Delivery is free over $50.

Thanks for your help.