Buyer has changed his shipping address on eBay

Such warning appears if shipping address is changed. Typically such situation appears if you set settings in eBay account for order creation rules to create orders when checkout is not completed. In this case the order is created in magento with default shipping address, but later when customer complete checkout and provide shipping address, this shipping address updated in magento order and m2e also put warning about this into orders in eBay > Sales > Orders

eBay Integration