setRebuildNeeded not having required effect

Problem/Motivation

Changing the path on an existing UI tab config entity causes an entity of the target type to crash:

Symfony\Component\Routing\Exception\RouteNotFoundException: Route "entity.node.entity_ui_set-owner4" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 208 of core/lib/Drupal/Core/Routing/RouteProvider.php).

Drupal\Core\Menu\LocalTaskDefault->getRouteParameters() (Line: 310)
Drupal\Core\Menu\LocalTaskManager->getTasksBuild() (Line: 358)
Drupal\Core\Menu\LocalTaskManager->getLocalTasks() (Line: 106)
Drupal\Core\Menu\Plugin\Block\LocalTasksBlock->build() (Line: 171)
Drupal\block\BlockViewBuilder::preRender()

This seems to be because the local tasks are trying to get hold of the new route, and it's not there.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes