Umlaut in username doesn't allow for "View Your Posts"

One of my users has an umlaut in her username and when she clicked on the "View Your Posts" link (when the variable at the end of the URL is "egosearch"), the first group of results would display. When she would click on "Next" or any of the numbered pages (when the variable at the end of the URL is her username with the umlaut), she would get an error saying "No Suitable Matches Were Found" even though she had plenty of other posts.

I tested this by adding an umlaut to my name and saw the same error. Without the umlaut, I saw all of my posts on all of the pages.

Attached is an image she made of three images (top - clicking the View Your Posts link, middle the results, bottom the error after clicking on a different page other than the first one).