I believe the problem is that the garbage collection doesn't ever kick in when switching scenes. So as you continue to switch between scenes, the number of allocated objects increase, thus resulting in a OOM.
Personally, I don't understand much about how garbage collection works for a multiplatform project/JVM myself so will need to do some research.
Also it seems like System.gc() is not available for a multiplatform project, so you can't activate garbage collection yourself.