@saito_y Did you find the solution?
I think I have found an Insight!
I found that ue4 save games were saved in the path.
/data/data/[PackageName]/files/UE4Game/[ProjectName]/[ProjectName]/Saved/SaveGames/SaveGame.sav
and ue5
/data/data/[PackageName]/files/UnrealGame/[ProjectName]/[ProjectName]/Saved/SaveGames/SaveGame.sav
It switched from UE4Game to UnrealGame!! And that’s why it did not find the save game!
So now I think it would work if we copy ue4’s SaveGame to the new directory!
Note that in my case I have turned on UseExternalFilesDir for UE4Games/UnrealGames
and for that, it was in /data/data…