NettSite on "[Plugin: Wordfence Security] PHP notice in error log."

I am getting a PHP notice in my error log while running WordFence Version 5.1.6 with WP_DEBUG = TRUE:

PHP Notice: ob_end_flush(): failed to delete buffer zlib output compression in /wp-includes/functions.php on line 2935

This happens with or without the Falcon caching engine enabled.

I haven't noticed this before, as in with previous versions of WordFence or WordPress.

https://wordpress.org/plugins/wordfence/