Errors upgrading to PHP8.1

Just upgraded to PHP 8.0 (same with PHP8.1) and this comes up on the admin page and also stops me edditing website in Elementor but disapears when I remove the woocommerce plugin or change back to PHP7.4.
Any help much appreciated!

Warning: Trying to access array offset on value of type null in /homepages/35/d82358935/htdocs/website/wp-content/plugins/woocommerce/src/Admin/Features/Navigation/CoreMenu.phpon line 246

Warning: Cannot modify header information – headers already sent by (output started at /homepages/35/d823589354/htdocs/website/wp-content/plugins/woocommerce/src/Admin/Features/Navigation/CoreMenu.php:246) in /homepages/35/d82358935/htdocs/website/wp-admin/includes/misc.php on line 1416

Warning: Cannot modify header information – headers already sent by (output started at /homepages/35/d823589354/htdocs/website/wp-content/plugins/woocommerce/src/Admin/Features/Navigation/CoreMenu.php:246) in /homepages/35/d82358935/htdocs/website/wp-includes/functions.php on line 6865

Warning: Cannot modify header information – headers already sent by (output started at /homepages/35/d823589354/htdocs/website/wp-content/plugins/woocommerce/src/Admin/Features/Navigation/CoreMenu.php:246) in /homepages/35/d82358935/htdocs/website/wp-includes/pluggable.php on line 1416

Warning: Cannot modify header information – headers already sent by (output started at /homepages/35/d823589354/htdocs/website/wp-content/plugins/woocommerce/src/Admin/Features/Navigation/CoreMenu.php:246) in /homepages/35/d82358935/htdocs/website/wp-includes/pluggable.php on line 1419

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