The parent issue is also happening with Drupal 9.5 and PHP 8.1. If you choose to not use the comment_body field of the module and you submit a comment, it will cause a PHP warning with an empty strip_tags parameter.
At a minimum, we should add a test: !$comment->comment_body->isEmpty() as applied on the parent issue to prevent the warning.
https://git.drupalcode.org/project/drupal/-/merge_requests/5871/diffs#35...
