Cal here from Shopify, thanks for reaching out to us. Be sure to include a link to your store for these sorts of requests so our community members can assist.
Thanks for adding that.
Currently, it is showing me both Euro, which is my local currency, and also GBP. You can see what it looks like for me here.
Hi again, it seemed to detect that Euro was my home currency and switched everything automatically. It showed in Euro in the basket, and also showed the converted figure in GBP. Which is a nice feature, as the next step in checkout it would show the store currency (which is GBP). I see nothing wrong with how the theme is performing. If you have any further queries about it, you should reach out to your theme developer and they can explain how and why it is performing this why.