Tenho o mesmo problema com comment_formatter.ERROR: e nem sequer tenho comentários do discourse ativados, nem ajax. Ele atinge os logs a cada 2 segundos, 24 horas por dia. Enquanto isso, muitos processos PHP lentos e um FLOCK que paralisa tudo, derrubando o site repetidamente.
script_filename = /www/index.php
[0x00007fa5ef613c90] flock() /www/wp-content/plugins/wp-discourse/vendor_namespaced/monolog/monolog/src/Monolog/Handler/StreamHandler.php:106
[0x00007fa5ef613c00] write() /www/wp-content/plugins/wp-discourse/lib/logs/handlers/file-handler.php:167
[0x00007fa5ef613b50] write() /www/wp-content/plugins/wp-discourse/vendor_namespaced/monolog/monolog/src/Monolog/Handler/AbstractProcessingHandler.php:34
[0x00007fa5ef613ad0] handle() /www/wp-content/plugins/wp-discourse/vendor_namespaced/monolog/monolog/src/Monolog/Logger.php:283
[0x00007fa5ef6139b0] addRecord() /www/wp-content/plugins/wp-discourse/vendor_namespaced/monolog/monolog/src/Monolog/Logger.php:614
[0x00007fa5ef613930] error() /www/wp-content/plugins/wp-discourse/lib/discourse-comment-formatter.php:62
[0x00007fa5ef613670] format() /www/wp-content/plugins/wp-discourse/lib/discourse-comment.php:310