``` is_feed was called <strong>incorrectly</strong>. Conditional query tags do not work before the query is run. ``` This is being triggered in WP 5.8 now with the addition of [`wp_should_load_separate_core_block_assets`](https://github.com/WordPress/wordpress-develop/blob/c7be2d875e0dfd355522efbaf3e4fca54947768a/src/wp-includes/script-loader.php#L2351-L2371)