This plugin seems to be calling wp_cron.php and getting a Header error

I’m getting this error in my logs:

Warning: Cannot modify header information – headers already sent by (output started at /home/nzin2020/dev.nzin2020.nz/wp-cron.php:23) in /home/nzin2020/dev.nzin2020.nz/wp-content/plugins/wpfront-notification-bar/classes/class-wpfront-notification-bar.php on line 63

The error actually seems to think the problem comes from wp_cron.php at line 23

fastcgi_finish_request();

If I comment out that line, then the header problem goes away. So it seems to be an interaction with fast cgi and headers…

Although my understanding is that wp_cron.php should NOT be being called by plugins.

And if it is, then there’s a problem???

I have checked for rogue spacing in wp_cron.php and it doesn’t exist.

Any ideas on this?

Thanks