PHP error log – Cannot modify header information

Hi
I am going through my php errors log and the 2 lines below have been around for a long time. I am trying to track them down and hopefully get them corrected.
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[03-Feb-2021 02:29:11 UTC] PHP Warning: Cannot modify header information – headers already sent in /home/*-removed-*/public_html/wp-includes/pluggable.php on line 1299
[03-Feb-2021 02:31:12 UTC] PHP Warning: Cannot modify header information – headers already sent in /home/*-removed-*/public_html/wp-includes/pluggable.php on line 1296
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When I look at pluggable.php – lines 1296 and 1299 have to do with redirection (see below) Is this caused by the Redirection plugin ? If so, how do I get these errors to go away?

1284		 * Filters the X-Redirect-By header.
1285		 *
1286		 * Allows applications to identify themselves when they're doing a redirect.
1287		 *
1288		 * @since 5.1.0
1289		 *
1290		 * @param string $x_redirect_by The application doing the redirect.
1291		 * @param int    $status        Status code to use.
1292		 * @param string $location      The path to redirect to.
1293		 */
1294		$x_redirect_by = apply_filters( 'x_redirect_by', $x_redirect_by, $status, $location );
1295		if ( is_string( $x_redirect_by ) ) {
1296			header( "X-Redirect-By: $x_redirect_by" );
1297		}
1298
1299		header( "Location: $location", true, $status );
1300
1301		return true;
1302	}
1303		endif;