Missing Option to Add Header Image

This is a vague question, I understand. If it’s also in the wrong place, I kindly request it moved and to be informed of its proper place or if more information is needed, feel free to request it.

My organization’s website has an events section and we want to put a header image on each event. Our theme for the site evidently supports a header image for an event page (I checked the appropriate php files, both the event-page specific template and the template that loads the event specific template support header images), yet there is no option to add a header image on the “Add New Event” page in the wordpress admin panel.

Any suggestions as to what may be going on here?