I did export/publish my (GLES2) project in Godot 3.2 successfully to Android. So there's no general problem in 3.2. (Except with input fields when no max length is set which is solved in 3.2.1)
There are however some changes from 3.1 to 3.2. I.e. concerning CPU particles.
In your case I'd go the usual way of android debugging. And that would mean either setting up godot to directly execute/debug your app (Editor settings -> Export -> Android, & then clicking the little robot which occurs when the device is connected via USB).
Or - probably more informative in this case - use "adb logcat" on the command line to list any log entries written on android (can be filtered).
See i.e. this post:
Sometimes the reason is quite simple:
1: Fails due to wrong character case or special chars in ressource name:
i.e. you have put "Startupwindow.tscn" in autoload but the ressource is actually named "StartupWindow.tscn". This would work in windows as it doesn't care about character case in file names but it fails on Android (and Linux). Same can happen with file names in load / preload statements.
2: Fails to load ressources which didn't make it into the apk for some reason:
Sometimes some ressources don't make it into the apk, or aren't signed properly. This can happen due to some exclude setting in the export.
Or - if it is a non-ressource file - it wasn't specified in the export include settings,.
Or it has special chars in the name and the jarsigner somehow fails to sign it.
The apk roughly is a simple zip file so you could use some unzip tool and check if at least the startup ressource files made it into the apk -> /assets (keep in mind that the some converted binary ressource files will be with a slightly cryptic name in the assets/.imports folder).
3: Some people actually try to write in the res:// folder:
This works in the editor but will fail on i.e. Android. Typically, you're supposed to write in the user:// folder.
4: You forgot to enabled some required privileges for your apk:
I.e. if you access the network then you need to enable the INTERNET privilege.