All tests passing except the ones that need to change.

src/wp-includes/html-api/class-wp-html-tag-processor.php

@@ -891,7 +891,7 @@ public function next_token() {
 		 */
 		$t = $this->html[ $this->tag_name_starts_at ];
 		if (
-			$this->is_closing_tag &&
+			$this->is_closing_tag ||
 			! (
 				'i' === $t || 'I' === $t ||
 				'n' === $t || 'N' === $t ||
@@ -911,7 +911,6 @@ public function next_token() {
 			'IFRAME' !== $tag_name &&
 			'NOEMBED' !== $tag_name &&
 			'NOFRAMES' !== $tag_name &&
-			'NOSCRIPT' !== $tag_name &&
 			'STYLE' !== $tag_name &&
 			'XMP' !== $tag_name
 		) {
@@ -1635,7 +1634,7 @@ private function parse_next_tag() {
 				$this->token_length         = $closer_at + 4 - $this->token_starts_at;
 				$this->text_starts_at       = $this->token_starts_at + 9;
 				$this->text_length          = $closer_at - $this->text_starts_at;
-				$this->bytes_already_parsed = $closer_at + 4;
+				$this->bytes_already_parsed = $closer_at + 3;
 				return true;
 			}