The reason is we have noticed both the display and touchscreen freeze after 3 months in our test suite so since these aspects do not share hardware it looks like the RTOS thread has latched.
I have performed a preliminary test to perform the thread terminate and restart every 5 mins and it appears to be safe, with just a short screen glitch as the hardware is reset.
I was also surprised that the display continued from the page it left and not at the home page which I suspect is because the model instances are held statically so remember their current actions. I trust this is expected behaviour as it's more than I expected.
