Calendar and Categories: Address Issues

When I click on the links for my Category and Calendar entries the website take me to an error page.

The problem has something to do with the link redirect. I notice in the address bar at the bottom of my page that I appear to be missing a “/”. For example, when I hover my mouse of my category labeled “General,” the address shows up as https://vcnielson.com/rhetoriccategory/general/ As best I can figure, there should be a “/” between “rhetoric” and “category”.

It has occurred to me that this might be cause by my WordPress Address not having a “/” in the address, but when I add one it is always automatically deleted. Beyond that I can’t figure out what action to take to fix this problem.