Thanks for the feedback. Any customers that are in you Shopify store will be searchable in Shopify POS, no matter how they made it there. I can't provide more help without divulging private information about your store on this private forum. Our support team will be able to help you for sure with this. You can reach Shopify POS support at: 1-888-678-9481 or email firstname.lastname@example.org.