My custom entity is revisionable, I can see revisions, but my revision revert form does not work. When I attempt to revert, I get the following error:

TypeError: Argument 3 passed to Drupalmsul_rovi_gamesFormRoviGameRevisionRevertForm::buildForm() must implement interface Drupalmsul_rovi_gamesEntityRoviGameInterface or be null, string given in Drupalmsul_rovi_gamesFormRoviGameRevisionRevertForm->buildForm() (line 116 of /opt/drupal/web/modules/custom/msul_rovi_games/src/Form/RoviGameRevisionRevertForm.php) 

I am not sure why it is not upcasting. I am sure I am missing something obvious, but hours of searching have not led me to what I am missing.

What am I missing? Any insight into why it is not upcasting would be greatly appreciated!

Relevant portion of msul_rovi_games.routing.yml

entity.rovi_game.revision_revert_confirm:   path: '/rovi_game/{rovi_game}/revisions/{rovi_game_revision}/revert'   defaults:     _title: 'Revert to an earlier revision'     _form: 'Drupalmsul_rovi_gamesFormRoviGameRevisionRevertForm'   requirements:     _permission: 'administer rovi_game entities'     rovi_game: d+   options:     _node_operation_route: TRUE     rovi_game:       type: entity:rovi_game     rovi_game_revision:       type: entity_revision:rovi_game 

Relevant portion of src/Form/RoviGameRevisionRevertForm.php

<?php  namespace Drupalmsul_rovi_gamesForm;  use DrupalComponentDatetimeTimeInterface; use DrupalCoreDatetimeDateFormatterInterface; use DrupalCoreEntityEntityRepositoryInterface; use DrupalCoreEntitySqlSqlContentEntityStorage; use DrupalCoreEntityEntityStorageInterface; use DrupalCoreFormConfirmFormBase; use DrupalCoreFormFormStateInterface; use DrupalCoreUrl; use Drupalmsul_rovi_gamesEntityRoviGameInterface; use SymfonyComponentDependencyInjectionContainerInterface;  /**  * Provides a form for reverting a rovi_game revision.  *  * @internal  */ class RoviGameRevisionRevertForm extends ConfirmFormBase {    /**    * {@inheritdoc}    */   public function buildForm(array $form, FormStateInterface $form_state, RoviGameInterface $rovi_game_revision = NULL) {     $this->revision = $rovi_game_revision;     $form = parent::buildForm($form, $form_state);      return $form;   } }