PHP Session Errors “Cannot start session when headers already sent”

I am seeing the exact same thing. It seems an approach is suggested here – https://ww.wp.xz.cn/support/topic/php-warnings-cannot-start-session-when-headers-already-sent/ – but not sure if it can apply to this plugin as well.

I get this error EVERY FIVE MINUTES (at each wp-cron.php execution which gets triggered with curl by system’s cron)…