saved asset not showing up in content browser after UPackage::SavePackage

[OrbitalZones]

I am trying to save an existing static mesh object to disk. The saving itself is working, however the created asset itself is not showing up in the content browser, even after a refresh (manual or by code).

This is the simplified code, currently used within a Blueprint function library. What is missing there or what might be wrong?

bool UStaticMeshFromProceduralMesh::SaveStaticMeshToDisk(UStaticMesh* StaticMesh, const FString& FileName)
{

    FString PackageName = FString::Printf(TEXT("/Game/%s"), *FileName);
    UPackage* Package = CreatePackage(*PackageName);

    StaticMesh->Rename(*StaticMesh->GetName(), Package);
    StaticMesh->MarkPackageDirty();

    FString PackageFileName = FPackageName::LongPackageNameToFilename(PackageName, 
FPackageName::GetAssetPackageExtension());

    bool bSaved = UPackage::SavePackage(
Package, StaticMesh, EObjectFlags::RF_Public | RF_Standalone, *PackageFileName, GError, nullptr, true, true, SAVE_NoError);

    return bSaved;
] 

I tried to use it with the SavePackageArgs as well, but there I get the same result - asset is saved on disk, but not visible in content browser

    FSavePackageArgs SaveArgs;
    SaveArgs.TopLevelFlags = EObjectFlags::RF_Public | RF_Standalone;
    SaveArgs.Error = GError;
    SaveArgs.SaveFlags = SAVE_NoError | SAVE_KeepGUID; 

    // Save the package
    bool bSaved = UPackage::SavePackage(
        Package,
        StaticMesh,
        *PackageFileName,
        SaveArgs
    );
 

[OrbitalZones]

The saved assets are now shown in the content browser. I changed the line

StaticMesh->Rename(*StaticMesh->GetName(), Package); to
StaticMesh->Rename(*FileName, Package);