The author of the submission only received the “Submission Confirmation” email; however, based on my understanding, they should have also received emails such as “Sent to Production,” “Sent to Review,” or “Submission Accepted”.
Could there be a reason these notifications were not sent, such as email preferences being disabled?
Is it possible those working in those stages did not send these notifications prior to moving it on to the next stages? It is possible in OJS for those messages to not be sent, depending on the activities of the users operating within those stages. What does it say in your activity log?
Is it possible that an editor bypassed these emails by skipping them and just forwarded the submission on to the next stage? This is feasible, provided they had the appropriate permissions.
That’s the most plausible solution that comes to mind.