Hi @YuyaShiotani! Thanks for the detailed report. I’ve been looking into this issue and having the video with sample code and steps to reproduce have been very handy!
The behaviour as displayed in the videos is actually as expected even if it doesn’t seem very intuitive, and perhaps it might be useful if I explain why. When you select to launch your UEFN experience we only try to upload the content in your source project which is actually being referenced by your experience. This is to reduce time spent uploading and makes it so content which won’t actually ever be included in the game doesn’t detract from your project size budget.
When you upload in the first case we recognize your SM_Box and SM_Cylinder aren’t included in the map or referenced by your verse source code so we don’t even upload them. Unfortunately this means when you attempt to use live edit to reference content which hasn’t been uploaded it doesn’t work correctly until you fully refresh, and you can see you get a warning in your editor output log for “LogValkyrieFortniteEditorLiveEdit: Warning: Asset reference replaced with proxy because it has not been uploaded yet: ‘StaticMesh /YourProject/Meshes/SM_Box.SM_Box’”.
You can verify this is what is happening by either placing those 2 meshes in the map before initially launching the experience, or add a reference to those 2 meshes somewhere in your verse code (even if you’re not actually using that reference to perform any logic). In both cases the repro shown in your video should work and live edit should update the reference to the new content correctly. I also tried this out myself and confirmed that it was working with either of those steps.
All this aside, replacing the end/start game in your video with a full ‘Push Changes’ (not just push verse changes!) should work. And a few of us have tried that here and it does work from what we can see. Can you try this out again and maybe provide a video of the repro using ‘Push Changes’ if you’re still hitting issues? Thanks!