maggie, I want to second what greg said below. This is the second thread we are seeing where this
%PUBLIC_URL% is causing problems - unfortunately, this is something to do with the tool you are using to build the site, and not Netlify, I dont think.
Here is the other thread:
In the readme, here: https://github.com/maggieprice/portfolio-main#using-the-public-folder it says:
can you tell us the build setting you are using to run things as part of your build step (your build settings)? It seems like CRA (create react app) isn’t substituting the URL the way it is supposed to.