I just looked at my save game system, and I am also storing Object references for some of my objectives. For me, these are actors permanently present in the world. I think it’s more problematic if you are saving created/spawned actors.
I looked more closely at your images and another thing I don’t like is the “Save Game to Slot” is within your For Loop. This seems problematic in theory. This node is serializing your data onto the player’s Hard Drive, so it seems possible the serialization process doesn’t play nice with the For Loop.
Ideally prepare the save data first then Save to Slot one time, at Completion of the For Loop for example.
I still don’t like the Add nodes they way you have them, data can get out of sync easily.
You can create Structs to hold sets of data.
I have a devlog from a couple months ago that explains some of my Save System for my current game, all in Blueprints, starting at 8:18. It’s not a tutorial so I don’t show absolutely everything, but maybe it helps: Majestic Devlog 6
Disclaimer: I’m not an expert 
This is what I would try.
1.) Create New Structure → Create 2 Variables: Actor and Transform in the struct.
2.) Add New Variable to Save Game Object → Variable type is your new Struct → Make it an Array
3.) In your Save Game Function → Add Local Variable → Type is your new Struct → Make it an Array
4.) In your Save Game For Loop, populate this Local Variable with Objects + Transforms
5.) On Completion of For Loop → Set Save Game Object → Make Variable in Object = Local Variable
6.) Save to Slot node after that
Test it - create print strings in your For Loops, for saving & loading, make sure the data is what you expect. If final actor is still not in its desired state, it must be a conflict at the end of the chain, the actor itself doing something after loading, or a timing issue where load happens before actor isn’t in the world yet.
With this method, the data stays together and you can even modify the Struct if you want to save more information for the actor.
Create additional structs for different types of assets you want to save.
For example, In my game I have 1 struct for the player character, 1 for my day/night system and 1 for primary objectives.