Ummm
Trickey, this automatically finishing/canceling a live flight plan, sounds like a variable system parameter needing a bit of tuning up. I would really need to almost talk it through to be able to identify the problem, but knowing the system that you have, it really should not cancel flight plans randomly or early. No I'm not a number cruncher - I hold an old ATC Licence from Aus - V119. However I've been involved with an upgrade of your system recently and although the data updating process is a bit painful, it worked.