Diacritical signs

In the Sonos Desktop Controller there is one place where the diacritical sign é does not display as it should, i.e. in the Genre section. To make it even more strange: it's only the é that is not being displayed, while the ë is being displayed as it should be. I've tried retagging, to no avail. In all other sections (Artists, Contributing Artists, Composers) the é is being displayed correctly.

I'd like to solve this mystery and welcome any and all suggestions and ideas.