Several objects on one build plate

I print the same part 36 times. So I spread it on two build plates. The first build plate is nearly finished and I had to skip several objects. And now I want to know what I could have done to prevent the failing of some objects?

The object im printing is Moss pole (pole_full_holes_new.stl)
https://www.printables.com/de/model/63803-moss-pole

The print is finish.
5 objects are in good condition
5 need a little bit of post processing:


And the rest is for the garbage:

I now printed the parts again, 20 mm apart from each other. All parts are perfect.