I am using CiviCRM 5.23.4 with Drupal 7.69, though this issue is not new to this version of Civi.
Every time Civi cron runs, I get a warning in the Drupal Recent log messages:
Warning: session_set_save_handler(): Cannot change save handler when session is active in drupal_session_initialize() (line 242 of /home/XXXX/www/www/includes/session.inc).
Any suggestions for how to address this would be appreciated. Thanks.