Edit button does not work when Entity does not define edit form

I had this issue when referencing Taxonomy Terms.
When an Entity does not define an edit form in the Entity annotations, the edit button does not work because the controller is looking for the edit form class. When debugging through core code, I noticed the following code:

      // Use the edit form handler, if available, otherwise default.
      $operation = 'default';
      if ($entity_type->getFormClass('edit')) {
        $operation = 'edit';
      }

This is part of the route generator for entity types. I edited the controller code to do something like this, and the edit button started working.