Issue: The extension is not working in IE 11. It just stays at "adding" Also it's not updating the mini quote section in the header.
We are using extension's version 1.0.3 on Magento 2.2.3.
The issue is caused due to the fact that our extension does not support the IE browser on Magento 2.2.x
To resolve this issue, we would like to give you the solution:
Step 1: Edit this file app/code/Bss/QuoteExtension/view/frontend/web/js/catalog-add-to-quote.js
Step 2: Replace that file on your site (check the attachment below)
Step 3: Flush the cache
If you need any assistance, please don't hesitate to contact us.