Amazon Fire 7 Tablet running out of space

Hi All,
I’m using an Amazon Fire tablet with Action tiles for an alarm panel. I have been using it for about 5 months and now the tablet is starting to complain about low memory. The only thing that is running is Fully Kiosk. When I go into the storage settings, 85% is being taken up by the system OS and not apps. Any ideas about what is bloating the OS and how to clean it up?