Magento 2.3 Add simple product manually to configurable product doesnt work

Our client didn't add simple products to configurable product and then didn't save the configurable product on admin page.   

Step by steps:

1. Go to admin page, edit configurable products 

2. Click "Add Products Manually" 

3. Picked some simple products 

4. Click Done button 

5. Click save button (configurable product could not save)

SOLUTION 1:

I found this solution. Reference link:

https://github.com/magento/magento2/issues/5172

Fixed Patch:

https://github.com/magento/magento2/commit/87b0a4bc1361fb315acb89d5a9f27e98b1bf6b74

SOLUTION 2:

I fixed the problem. In admin, edit product, click Advanced Inventory -> Maximum Qty Allowed in Shopping Cart is set = 0. I changed the value to 9999 and solved the problem.

Checkout page is not working on IE (magento 2.3.3)

The checkout page didnt work on IE. The page was loading forever.
I found a lot of solutions and some reference links:

1. Disable Full Page Cache (i think this will turn off fastly cache as well)

https://community.magento.com/t5/Magento-2-x-Technical-Issues/Magento-2-Internet-Explorer-Loader-Stuck-at-Checkout/td-p/111501

2. Increase cookie life time on System >> Configuration >> General >> Web >> Session Cookie Management >> Cookie Lifetime

https://stackoverflow.com/questions/22529196/magento-checkout-doesnt-work-in-internet-explorer-10-with-windows-8 

SOLUTION 1:

I found this link

https://github.com/magento/magento2/issues/23837

The fix will be available with the upcoming 2.3.4 release.

Patch fix:

https://github.com/magento/magento2/commit/6d642f83ad5551d5adc52930a227e66b87ddf480

SOLUTION 2 (GOOD):

Follow the patch 

diff --git a/vendor/magento/module-paypal-captcha/view/frontend/web/js/view/payment/list-mixin.js b/vendor/magento/module-paypal-captcha/view/frontend/web/js/view/payment/list-mixin.js
index 60172f696e9..8abd57cc691 100644
--- a/vendor/magento/module-paypal-captcha/view/frontend/web/js/view/payment/list-mixin.js
+++ b/vendor/magento/module-paypal-captcha/view/frontend/web/js/view/payment/list-mixin.js
@@ -34,14 +34,16 @@ define([
 
         /**
          * Overrides default window.clearTimeout() to catch errors from iframe and reload Captcha.
+         *
+         * @param {Number} timeoutID
          */
-        clearTimeout: function () {
+        clearTimeout: function (timeoutID) {
             var captcha = captchaList.getCaptchaByFormId(this.formId);
 
             if (captcha !== null) {
                 captcha.refresh();
             }
-            clearTimeout();
+            clearTimeout(timeoutID);
         }
     };