Why would the review system status go from "awaiting recommendation" back to "awaiting referee assignment"? I recently submitted my first  paper to a philosophy journal. After about a month, 
the status switched from "Awaiting Reviewer Scores" to "Awaiting recommendation". Then a few days later it switched back to "Awaiting referee assignment" again. Thus, seemingly, the review process ended only for a second one to be initiated by the EA just days later. 


Why would the system change back to "Awaiting referee assignment"?
Does this mean that EA has sent the manuscript out for a second review?
Why would the EA send the manuscript out for a second review?
Is the EA unsatisfied with the referees' report, so he wants to get an additional review?
What could also have happened is that the initially assigned reviewer first accepted to review the paper, only to then forget to do so. At the end of the time that he/she had for the review, the journal editor might have sent a reminder only to then receive an apologetic note stating that the reviewer does not have the time to do so - then the editor would have to find a different reviewer. All these things have happened. If you want to make sure what is going on, you can always send a friendly note to the journal editor and ask about it. They are human after all.