By the way:

"Microsoft will say goodbye to Internet Explorer and Edge Legacy in 2021"

"From the exit of the first Edge, Microsoft no longer labeled the old IE as a ‘browser’, but as a “compatibility fix” and began to encourage companies to stop using it.

The company announced a few hours ago that it will no longer guarantee the compatibility of its Microsoft 365 applications and services with Internet Explorer 11 as of August 17, 2021. And long before that, on November 30 this year, it will no longer be supported by Microsoft Teams."

https://www.explica.co/microsoft-will-say-goodbye-to-internet-explorer-and-edge-legacy-in-2021/

We are doing our best to ensure compatibility with older browsers, however, due to technical limitations, it's not always possible.

If we decided to fully support old browsers, we would neglect the development and improvement of our products.

As you can see all modern frameworks (including Bootstrap 5) drop support for IE and we cannot provide full compatibility for such old browsers. We will always try to do it as the best effort, but we cannot sacrifice development and improving our products for the sake of the browser that even Microsoft itself has abandoned.