Tira here, from Shopify Support.
Have you contacted PayPal Support to see if you can modify the "ebay" name to your store's name? You can contact them here through this link: Contact PayPal Support.
Once you have more information from their support about this name change, I would love to hear more about what information was given to you. If they mention that this is related to Shopify, please let us know by replying to this thread and I can look at this in more detail for you.