Villagers randomly despawing

Hi, I have just raised a report on 

1. MCPE-21416

But then I read tha tis has been closed and won't be reopened?  Can you advise if I need to enter a new report please, or leave it on the one that seemed the most similar?  Thank you.

I have had 4 villagers despawn in a week, 3 today.  They are converted natural zombie villagers (not from a spawner).  They were named, and traded with.  Trapped in a one block space and have not interacted with any other mob.

 

Full description and image can be found on the above report.  Thank you Cjsgoose