Q: What does 'EIC: Not Assigned' along with 'Under Review' mean?

This dual status is a bit unusual, but it does happen.

To explain each status, ‘EIC: Not Assigned’ means that the EiC (the Editor-in-Chief) has not been assigned to the manuscript. Based on the journal, ‘Under Review’ means that the manuscript is undergoing an internal (journal) review or an external (peer) review. In this case, the manuscript is probably going through an internal review to see if it fits within the scope of the journal. This is usually done by the administrative team or by the Associate Editor (AE), who is typically the main person overseeing the manuscript.

So, the status probably means that the AE is reviewing the manuscript, but hasn’t yet made a decision on whether to send it for peer review or to reject it. If they decide on the latter, they will then perhaps change the status to ‘EIC: Assigned’ and refer their decision to the EiC. Note that the EiC makes the final decision on the manuscript, not the AE. So, in short, there is no decision yet on your manuscript. You simply need to wait and watch. :-)

Until then, you may learn more journal statuses by referring to these resources:

• What does the status "ED: Not Assigned, EE: Under Review" mean on ScholarOne?
• Does "Under Review" mean that the paper has passed the editorial check?
• A guide to understanding journal statuses [Handbook]

Hope that’s helpful. All the best for the next update!