When this happens, the address is auto-populating from saved addresses that you have on your device, or saved addresses that you have created within ShopPay, AmazonPay, PayPal, ApplePay etc.
To prevent this, you can update these addresses either on your specific device or, go into your payment app to update with the correct address.
Be sure to verify that your shipping address is correct before you submit your order. Unfortunately, Lems is not responsible for orders that have the wrong shipping address on the order.
Here is a related article, Can I make changes to my order or cancel my order after it has been placed?