UE5 - Meta Quest, can't create file in internal storage in shipping builds

[jback]

I'm trying to use SQLite in an Unreal project targeting Meta Quest 3. It would require creating a .db file in the headsets internal storage, something that I'm not getting to work properly at all.

As a test I'm scaling back just trying to create a simple .txt file just to get the file creation to work. (See code below) This seems to work in Development builds but not Shipping builds. I need to get it working in shipping builds.

I've tried both with and without the "UseExternalFilesDir" flag in UE, I've tried setting WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE but nothing seems to work. I'm not finding any info of the difference in file storage in Dev/Ship builds. I've tried various directories such as "ProjectSavedDir()" as well as hardcoding paths like "/sdcard/testing".

I'm running out of ideas, does anyone have any insight into these issues?

UE 5.3

//CREATE OUTFILE
FString TempString = FString(TEXT("Hello World"));
FFileHelper::SaveStringToFile(TempString, *(FPaths::ProjectSavedDir() + "OutFile"));