I have noticed this in multiple jme based apps (my LSF one and @Tryder Space Rocks).
After screen is locked and unlocked while the app is running, childs of guinode just disappear.
I’d need to test if they are just detached or gone entirely.
Another thing I have noticed is that after screen is unlocked, there is the image set as splash screen overlaid over everything. I made a workaround for that by manually setting its visibility in onResume(), but that should not be happening.
I also noticed with my true type font library after locking the screen with the app running and then unlocking it the texture atlas is messed up, probably was removed from memory. This happens when locking the screen with the lock button, but if you wait for the screen to lock on its own and then unlock the screen it’s not a problem.
This issue happened on my phone, but was not a problem on my tablet. My tablet is on Android 4.4 and my phone is on 5.0.
Well in my tests the issue is present on both HTC Desire 728g (Android 5.1) and Archos something something (tablet, Android 5.1).
I heard Google made some changes to memory management with 5.0 to make Android more friendly to devices with little memory, maybe this has something to do with it.
Could you maybe make a tiny test Case?
Also print the state changes, maybe stop () is called when locking the screen.
Also you could include a simple Println of the gui object in the simple update to see if the Element is null and also getParent the cullhint etc
For a test case I think you can just use the default template. When you lock the screen and bring it back up you’ll notice the stat display is missing.
Is that also replicable with the Emulator?
That I wouldn’t know, I did all my testing on my phone and tablet as I wasn’t able to get the emulator working at all with jME.
I don’t have my laptop in front of me, but I think the emulator spit out something about GLES when trying to run a jME app, probably my old laptop.