peridoic settings reset

[lvm]

Fiirefox for android stable periodically starts in the configuration which is quite different from the usual, e.g. the annoying 'top sites' tab is present - it is turned off in my setup, and the menu is shorter than usual with no Quit. Restarting Firefox (e.g. force stop in app manager) restores normal settings. How can I stop this from happening? Usually I don't leave Firefox running and exit it via quit.