mage-cache-storage clean after reload page magento 2.1 checkout

Question

I input some information at the checkout. It write in mage-cache-storage. When I reload checkout page mage-cache-storage are clearing. Why is this happening? How I can fix it? Thanks in advance.

I found core file for testing. Path is: vendor/magento/module-checkout/etc/frontend/sections.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © 2016 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Customer:etc/sections.xsd">
    <action name="checkout/cart/add">
        <section name="cart"/>
    </action>
    <action name="checkout/cart/delete">
        <section name="cart"/>
    </action>
    <action name="checkout/index/index">
        <section name="checkout-data"/>
    </action>
    <action name="checkout/cart/updatePost">
        <section name="cart"/>
    </action>
    <action name="checkout/cart/updateItemOptions">
        <section name="cart"/>
    </action>
    <action name="checkout/cart/couponPost">
        <section name="cart"/>
    </action>
    <action name="checkout/cart/estimatePost">
        <section name="cart"/>
    </action>
    <action name="checkout/cart/estimateUpdatePost">
        <section name="cart"/>
    </action>
    <action name="checkout/onepage/saveOrder">
        <section name="cart"/>
        <section name="checkout-data"/>
        <section name="last-ordered-items"/>
    </action>
    <action name="checkout/sidebar/removeItem">
        <section name="cart"/>
    </action>
    <action name="checkout/sidebar/updateItemQty">
        <section name="cart"/>
    </action>
    <action name="rest/*/V1/carts/*/payment-information">
        <section name="cart"/>
        <section name="checkout-data"/>
        <section name="last-ordered-items"/>
    </action>
    <action name="rest/*/V1/guest-carts/*/payment-information">
        <section name="cart"/>
        <section name="checkout-data"/>
    </action>
    <action name="rest/*/V1/guest-carts/*/selected-payment-method">
        <section name="cart"/>
        <section name="checkout-data"/>
    </action>
    <action name="rest/*/V1/carts/*/selected-payment-method">
        <section name="cart"/>
        <section name="checkout-data"/>
    </action>
</config>

And added here

<action name="checkout/*">
 <section name="checkout-data"/>
</action>

Answer 1

Magento assumes that customer's private data is changed when a customer sends some state modification request (POST, PUT, DELETE). To minimize the load on server, developers should specify which action (or request) updates which customer data section in etc/section.xml.

<action name="checkout/cart/add">
    <section name="cart"/>
</action>

• https://magento.stackexchange.com/a/143381/69

Also further reading:

• Magento 2: Syncing Backend and Frontend State/Cache