Thank you for these details,
I looked into this and into our code, but from everything I can see, B2BKing would not normally have any effect on this Order email. Therefore I doubt the issue is directly connected to our plugin. Possibly the issue started before installing our plugin, but you did not notice it immediately.
Please follow these steps:
1. Deactivate the B2BKing plugin, and test again to see if the emails are being sent or not. B2BKing has no permanent effects during installation, so by deactivating the plugin and testing, you can check if the issue is directly connected to B2BKing or not.
2. If you can indeed see a direct connection, meaning that emails are sent when B2BKing is active, and not sent when deactivated, then we’re happy to look further into it. In that case, we’d ask you to open a ticket with us at https://webwizards.ticksy.com and please provide us with a backend login to your site or a staging site, so we can directly investigate the issue.