Hello!
Thank you for your response. I was able to solve the issue thanks to the suggestion, so I’ll post the info here for anyone in the future who might have the same problem:
The staff member who was not receiving the notifications was using the web version of Outlook, and had blocked our WPForms sender email somehow.
Unblocking the email address did not immeditaly solve the issue, but doing a settings reset and adding a rule that pinned messages to the top of her inbox did.
Afterwards we were able to turn off the rule and the notifications worked fine.
Thanks again for pointing me to where I needed to go!
