I can confirm that this, in my case, was the WPML issue highlighted by @miili
After making the suggested changes everybody is now receiving ‘New Order’ emails again.
I see this problem as well after upgrading to 5.0.0. This has always been working fine up until now. From my Mailgun logs, it does look like it sends to the customers but the three emails I have set (as comma separated) on ‘New Order’ email do not receive new order emails. These are not in the logs in Mailgun either.
