Localised currency changes back to default after product is added to cart

Hello, we are using this plugin. The default currency is Euro, however it is set to localise depending on the customers location. Eg. if a customer is in the UK, the store will show with ￡ prices. However, when they add a product to the shopping cart and go to checkout, all the prices revert back to €. This is extremely confusing and off putting for the customer. How do we fix this?