media_library filter giving Access denied

I'm not totally sure this is the same problem but I'm still getting access denied on admin/content/media-widget-table in D 9.5.8

The error in the logs is

Path: /XXXX/en/admin/content/media-widget-table. Drupal\Core\Http\Exception\CacheableAccessDeniedHttpException: The opener ID parameter is required and must be a string. in Drupal\Core\Routing\AccessAwareRouter->checkAccess() (line 118 of /XXXX/core/lib/Drupal/Core/Routing/AccessAwareRouter.php).

still an issue D 9.5.10

The error in the logs is

Path: /XXXX/admin/content/media-widget/image?name=xx&sort_by=created.Drupal\Core\Http\Exception\CacheableAccessDeniedHttpException: The opener ID parameter is required and must be a string. in Drupal\Core\Routing\AccessAwareRouter->checkAccess() (line 118 of /XXXX/core/lib/Drupal/Core/Routing/AccessAwareRouter.php).

When we ran into this issue it was for a piece of content that had maybe a hundred paragraphs, most with images in them— but i think it is reasonable to expect that what happens in any given media widget should be unaffected by the context from where that widget was called.

And the cause was this, as found in the Apache web server log:

Got error 'PHP message: PHP Warning: Unknown: Input variables exceeded 1000. To increase the limit change max_input_vars in php.ini. in Unknown on line 0', referer: https://example.com/node/16/edit

Increasing max_input_vars to 2000 fixed it for us.