DB error after upgrade

I’ve upgraded CoAuthors Plus today, and some DB errors appear on the /author/… pages. But the behaviour isn’t the same on every page:

– on some pages nothing works:

Erreur de la base de données WordPress : [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '34 OR (wp_term_taxonomy.taxonomy = 'author' AND wp_term_taxonomy.term_id = '4011' at line 1]
SELECT SQL_CALC_FOUND_ROWS wp_posts.ID FROM wp_posts LEFT JOIN wp_term_relationships AS tr1 ON (wp_posts.ID = tr1.object_id) LEFT JOIN wp_term_taxonomy ON ( tr1.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id ) WHERE 1=1 AND ((wp_term_taxonomy.taxonomy = 'author' AND wp_term_taxonomy.term_id = '2087'34 OR (wp_term_taxonomy.taxonomy = 'author' AND wp_term_taxonomy.term_id = '4011'))) AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish' OR wp_posts.post_status = 'private') GROUP BY wp_posts.ID HAVING MAX( IF ( wp_term_taxonomy.taxonomy = 'author', IF ( wp_term_taxonomy.term_id = '4011' OR wp_term_taxonomy.term_id = '2087',2,1 ),0 ) ) <> 1 ORDER BY wp_posts.post_date DESC LIMIT 0, 15

Warning: Cannot modify header information - headers already sent by (output started at /homepages/32/d352289472/htdocs/wp-includes/wp-db.php:1398) in /homepages/32/d352289472/htdocs/wp-includes/pluggable.php on line 1216

– on some others it works perfectly: https://www.trensistor.fr/author/rcerda/

And what is weird is that it seems that the problem only occurs when I’m logged in with the administrator account…

Does anybody have an idea of what causes the bug?
Thanks!