As the attachment image displayed, when I click the dropdown list in place 1 to change the key value, it will change the key value in place 2. the key value in place 1 will not change.
Step to reproduce:
1) Create a class inherited from SerializedScriptableObject
2) Embed a field with generic Dictionary<>
3) Create two elements in this Dictionary
4) Try to create the third element, when you click the dropdown in new element editor (place 1), it will change the key value of the last element in the dictionary.
Unity 2017.1, Odin (22.214.171.124, a patch version sent from you), OSX 10.12.4