Q: What does a status change to 'Evaluating recommendation' from 'AE assigned, under review' mean?

I think this journal uses the term 'under review' to refer to both internal and external review. Even when the editor was not assigned, the term 'under review' was used. I think the first status update 'AE not assigned, under review' was used to refer to the initial admin check that is done by editorial assistants before the paper is sent for review. The second status update 'AE assigned, under review'  was probably used to indicate the initial editorial screening. However, there was no change to 'Reviewers assigned' after that. This makes me think that the paper has not yet been sent for peer review. Generally, the status 'Evaluating recommendation' is used when the AE is making his/her recommendation on the paper. Thus, it seems that the AE is taking a decision on your paper whish he/she will pass on to the Editor-in-chief (EiC). Unfortunately, this seems to be an indication that your paper has not cleared the editorial screening. The next status will make things clearer. If the status changes to 'Reviewers assigned,' it will mean that your paper has been sent for peer review. However, if the status changes to 'Decision in process,' it will mean that your paper will be desk rejected.