UT like LevelSummary, FLinker::Preload fails

Hi,
For our project i wrote a Levelsummary system like the one implemented for UnrealTournament. As i can’t share my code right now, i will point to the parts in the UT code(since all i had to change was how to get the assets from the AssetRegistry, a bit). For UT they extended the WorldSettings class, and added a property LevelSummary which holds all the SummaryValues. During runtime, they extract this LevelSummary-Object from the map, without loading it completely.
This is the summary-object:
UTLevelSummary.h
This is their WorldSettings which uses the object as aggregation:
UTWorldSettings.h
And this is the code for loading the summary-object at runtime. In my code i moved it from the Gameinstance to a FunctionLibrary:
UUTGameEngine::LoadLevelSummary

The problem i am facing is, that the code seems to work fine. Until i package the game or cook the content. Then the following will fail:

Linker->Preload(Export.Object);

Assertion failed: InPos >= 0 && InPos <= TotalSizeOrMaxInt64IfNotReady() [File:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Serialization\AsyncLoading.cpp] [Line: 7183]

Has anybody an idea on why this happens?

Hello, did you ever find a solution to this? I am currently experiencing this on 4.18.