Hey Jamie,
Welcome back and sorry to see emails are not getting delivered. Do you have a plugin like Easy WP SMTP installed which helps ensure emails get delivered? If not, I highly recommend checking it out. I use it on all my test and live sites.
I’d also visit your WooCommerce > Settings > Email page to ensure things are set up properly there. Have you tested to see if RSVP emails come through? If not, would you mind giving that a shot? It would also help if you could include your System Information as a private reply.
Keep me posted and have a good evening. Cheers!