There is an occasional warning entry in the error_log file generated. Can you please check for the condition that generates the error so this isn’t generated?
PHP Warning: Attempt to read property “display_name” on bool in /***/****/public_html/blog/wp-content/themes/graphene/inc/comments.php on line 232
This is on WP 5.9.1 with Graphene 2.8.6 running on PHP 8.0.16
Thanks for your great work!