Ever since WordPress updated to 5.5, it seems like the all the “>” greater-than symbols are being encoded into the HTML ampersand code of “>” and also displaying on the client as “>” and not as the appropriate “>” sign thus messing up the styling. I am assuming its some sort of issue with saving the content in an HTML form POST.
I did notice, however, that the code in Customize > Additional CSS saved and displayed the greater-than symbol fine, so as a workaround I just copied the CSS code from the Custom CSS to the Additional CSS section and it works now, but just a heads up on this problem.