TempFiles in .obb file when generate patch

Hi,

I use Unreal Frontend to generate a patch of my game, and I got a new .apk and .obb file in [Project Name]\Binaries\Android\ folder. But the file size of patch .obb is much larger then release one. I use 7-zip to unzip the .obb file and found there is a [Project Name]\Content\Paks\TempFiles\ folder and a .pak file in the patch .obb file. It seems that the .obb file is generate by zip all contents under \Saved\StagedBuilds\Android_ETC1[Project Name]\Content\Paks\ folder by Unreal Frontend during the packaging process. But there is no TempFiles folder when build a release. Did I miss any setting? A bug of Frontend? Or I can just ignore that .obb file and just use .pak file under \Saved\StagedBuilds\Android_ETC1[Project Name]\Content\Paks\ folder?

Whole Process:

  1. Build a release of my game.
  2. Modify some contents.
  3. Build a patch based on release(step 1).

Thanks : )

Is any developer meet the same issue??