word fence reports a gzinflate error

[May 29 11:06:43] gzinflate(): data error (2) File: /xx/xx/Website SdW/wp-includes/class-http.php Line: 1963

I contacted my provider to see if we are hacked, answer no, and he suggested I contact the developer.

Line 1985 till 1979 read:

public static function decompress( $compressed, $length = null ) {

		if ( empty($compressed) )
			return $compressed;

		if ( false !== ( $decompressed = @gzinflate( $compressed ) ) )
			return $decompressed;

		if ( false !== ( $decompressed = WP_Http_Encoding::compatible_gzinflate( $compressed ) ) )
			return $decompressed;

		if ( false !== ( $decompressed = @gzuncompress( $compressed ) ) )
			return $decompressed;

		if ( function_exists('gzdecode') ) {
			$decompressed = @gzdecode( $compressed );

			if ( false !== $decompressed )
				return $decompressed;
		}

		return $compressed;

I compared this to an original WP file, and it seems to be identical.

Why does this get flagged?

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