We Noticed that selected shipping address is saved when clicked 'Next' on checkout/#shipping page in quote_address table. The address is changing to customer_address_entity data if the customer clicks browser refresh button or F5 when on the payment page. The quote_address is not getting updated even after the refresh, it's an issue with browser display, so not sure what's going on. Any clues on how to identify the code that's switching address upon refresh in Magento 2.2.x?
This will only happen when there is 1 or more addresses in customer profile.
It maybe possible to add an observer as mentioned in this post reset address issue but trying to understand the root cause.