IE vs Edge display differences

Why would a website being run in production mode look different between Edge and IE? I guess this has something to do with the documentation at https://vaadin.com/docs/v13/flow/production/tutorial-production-mode-basic.html#what-is-transpilation-and-bundling, just don’t understand how to predict what visual differences I should expect, or how to minimize the differences as much as humanly possible.

You can see the examples of the differences I am seeing at https://vaadin.com/forum/thread/17753834/17776976.