Waiting for an overdue review? I have submitted my paper on 12-Jan-2019. The journal uses ScholarOne Manuscripts for online submission. The status has been changed to Awaiting Reviewer Scores in the same week I created the submission. 

I've recently contacted the editor about the status of the manuscript on 8-Apr-2019 and he replied that he is waiting for an overdue review, the the reviewer wa chased on 5-Apr-2019.

At this point, I know I should wait. But it's interesting to know if I can send another reminder and when should I do that. Especially when the editor actually reported what is going on and didn't simply mention that the paper is "Under Review" and I should leave it like that until a decision is made.
You can send another reminder, but I would wait a bit. It is an uncomfortable thing to do, and my own level of discomfort with sending such notes usually gets outweighed by my impatience at around the 2-month mark. So, if you don't hear anything back by early June, you might write again.

But different journals and different fields have different typical timelines, so you will need to come to your own decision about the timing.