On Update previous nested objects are recreated

[mfts]

When I'm creating a object with a nested object via nested_form_fields everything works well.
When I go to edit but don't change my inputs, a new and identical nested object is created.

Rails 5.0.1, Ruby 2.3.1, Mongoid 6.1.0

[ncri]

My guess is you didn't allow the id of the nested elements in permitted parameters. You might also need to add a hidden id field in the nested forms. It should all work fine then. If no id is submitted or the id is not a permitted parameter, rails thinks the submitted object is a new record.