Just an update.
I could identify that this issue only happens when i try to delete the objects for only one region. If i do the same but for the second region it just works. Any ideas where can i see logs about these operations?
I just had to re-deploy whole NSX on version 188.8.131.52. The only thing i can imagine that could break this was the upgrade from NSX 3.0 to 184.108.40.206.
With a new installation everything started working again.